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1957
The Lepidopterists' News
29
ON THE QUESTION OF A LECTOTYPE FOR MEGATHYMUS ARYXNA DYAR*
by Curtis W. Sabrosky
In 1955 dos Passos and Bell published an application to the International Commision on Zoological Nomenclature to fix the lectotype of Mega-thymus aryxna Dyar (1905). Far from being of limited scope, this problem is one of general interest. Every taxonomist meets with problems of the composition of original type series, restriction, and lectotype selection. In the absence of predominant and important usage which it is desired to preserve, a ruling on this application can and should be made on the basis of general principles that will guide all taxonomists faced with similar problems.
For details and review of the literature, the interested reader should consult the papers by Bell and dos Passos (1954), dos Passos and Bell (1955), and Stallings and Turner (1954, 1955). The argument revolves about the original description, which is repeated here:
"M. aryxna, new species.
"This is the form figured in the Biologia Cent.-Am. Lep. Het., Ill, pi. 69, figs. 3 and 4. It differs from neumoegeni in having the fulvous markings considerably reduced, the outer band being broken into spots. I have ten specimens from Arizona from Dr. Barnes and Mr. Poling....."
ORIGINAL TYPE SERIES OF MEGATHYMUS ARYXNA DYAR
From the original description I consider that there are two reasonable alternatives as to what constitutes the original type series:
(a) The ten specimens from Arizona which Dyar had before him, but not the Biologia specimens which he (as far as anyone can tell from his words)' knew only from the figures; and
(b) The ten Arizona specimens plus the two Biolog:a figures which Dyar identified as being of the same species as his Arizona material.
I cannot conceive of the original type series of aryxna being limited to the two figured specimens of the Biologia reference, as concluded by dos Passos and Bell. Decision 142 of the 1953 Copenhagen Congress, to which they refer, applies only to those instances in which "a specific name, when first published, is expressly stated to be a substitute (e. g. by the use
* This paper is only slightly modified from that printed in Opinion 483 of the International Commission on Zoological Nomenclature and was in press when that Opinion appeared. That Opinion directed that only the two Biologia figures in question are to be accepted as syntypes of Megathymus aryxna Dyar, and that the specimen from Mexico upon which figure 4 is based is to be accepted as the lectotype of aryxna. The Opinion was based on, although not (in my opinion) inevitable under Declaration 3 5 (issued at the same time) in which the Commission dealt with the meaning of the expression "syntype" as used in the Rules.
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of such expressions as 'nom.nov.' or 'nom.mut/) for a previously published name . . ." (Italics mine except for the abbreviations). Dyar's aryxna, however, was not expressly stated to be a substitute for neumoegeni; on the contrary, it was clearly proposed as distinct from neumoegeni, both in description ("It differs from neumoegeni in . . .") and in the key immediately preceding it.
From a commonsense viewpoint, it would have been contrary to human nature for Dyar to base his new species entirely on two pictures, leaving the ten specimens actually before him without any standing! It would have been far more logical, and indeed in accord with common practice, for him to describe aryxna from the ten specimens only, with the comment that it was the species figured in the Biologia, but with no intention of including the figured specimens in his type series. As a matter of fact, the ten specimens from Arizona, in the collection of the U. S. National Museum, are all marked with the distinctive red label "Type No. 13033 USNM" (in this case "type" — syntype), and were so entered in the Museum's Type Catalogue on February 28, 1910, by Dyar himself. Granted that labeling per se is not an effective nomenclatural action, it does show clearly what Dyar himself considered to be the type series upon which his species was based. Barnes and McDunnough (1912) took the same view.
In conclusion, the first alternative probably more accurately reflects the facts of the case, it seems to me to be the more logical choice, and it may even be the inevitable one because of the publication by Barnes and McDunnough (1912). The second is possible if one considers that Dyar also had the two figures before him, even if not the actual specimens.
RESTRICTION OF ARYXNA UNDER THE FIRST ALTERNATIVE
(Type scries = the ten Arizona specimens)
Skinner's (1906, 1911) synonymy of aryxna with neumoegeni was a subjective zoological action which still did not pin down the actual type series of aryxna, although he did eliminate the Biologia figure 3 as belonging to a distinct species (named M. drucei in 1911).
The first valid restriction is that of Barnes and McDunnough (1912), who unquestionably and clearly recognized that aryxna was based on a mixed series, and restricted the name to one of the component parts. At their request, Dyar "restricted the name aryxna' (by labeling) to that part of the series which was not neumoegeni. Although Dyar himself did not publish the restriction, Barnes and McDunnough suggested the restrictive action and did publish it, and published a figure of aryxna sensu stricto, based on a "co-type" (=syntype) (plate 1, figs. 1,2). They also clearly indicated the restriction by the following citations under the various species:
1957
The Lepidopterists' News
31
p. 21, Druce's Bioiogia fig. 4 cited under neumoegeni;
p. 22, aryxna Dyar, partim, cited under neumoegeni;
p. 26, aryxna Dyar recognized as a valid species {aryxna Dyar, partim) ;
and p. 42, drucei Skinner (Bioiogia fig. 3) is said to be possibly the female
of smithi, or else a distinct species.
We can scarcely hope for clearer restriction of a mixed series. (See discussion below on the nomenclature of restriction.)
I do not agree with DOS Passos and Bell in finding any significance in Barnes and McDunnough's use of the expression "unnamed form" (1912, p. 23: "Dr. Dyar restricted the name aryxna to the unnamed form"). Barnes and McDunnough found "two forms, both included in the type series of aryxna." One was the true neumoegeni, but for the second there was no earlier name available (hence, "the unnamed form'), and they suggested that Dyar restrict the name aryxna to this part of the series. That conservative taxonomic pratice utilized the already published name "aryxna" and admirably avoided the necessity of proposing a new name for the "unnamed form".
The lectotype selection by Skinner and Williams (1924) would be invalid under the first alternative, because the specimen from Mexico (basis of Bioiogia fig. 4) was not one of the ten specimens from Arizona, and hence was not part of the original type series.
Stallings and Turner (1954, plate 3) showed two figures of "M. aryxna Type $ as restricted by Dyar." This might be considered the first valid lectotype designation for aryxna under the first alternative. On the other hand, because they referred to the "Holotype" of two other species, and were careful to designate a "Lectotype" for neumoegeni, it might be argued that their "Type" for aryxna was used only in the sense of "a type" — i. e., a syntype — and merely quoted information on the specimen's label. Under the latter view, a lectotype is still not fixed for aryxna; under the former, a lectotype was established. Incidentally, Stallings and Turner stated (p. 78) that aryxna in Barnes and McDunnough's restricted sense includes only four of the original ten specimens.
RESTRICTION OF ARYXNA UNDER THE SECOND ALTERNATIVE
Under the second alternative the first reviser of aryxna is apparently Skinner (1906, p. 112): "M. aryxna Dyar is a synonym of neumoegeni, Edw. The fig. 3, pi. 69, Biol. Centr. Amer. Het. is not neumoegeni, as stated by Dyar." This action eliminated fig. 3 and restricted aryxna to fig. 4 and the ten specimens. Skinner (1911) continued his 1906 treatment by proposing for fig. 3 the new specific name drucei and treating aryxna as a variety of neumoegeni.
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The next revision of the species was made by Barnes and McDunnough (1912) (see under first alternative). They clearly restricted aryxna to a species represented by certain specimens in the Arizona series, of which they figured a ucot}/pe" (=syntype) as an example.
The lectotype selection by Skinner and Williams (1924) would not be valid under the second alternative, because the specimen from Mexico is not in the type series as restricted by Barnes and McDunnough (1912).
Again we come to Stallings and Turner (1954), and the remarks made under the first alternative apply here also.
LECTOTYPE OF M. ARYXNA
For both alternatives the conclusion is the same: The final restricted type series of aryxna consists of four specimens from the Arizona series orignally studied by Dyar. Depending on interpretation, either a lectotype has been fixed by Stallings and Turner (1954) or no lectotype has yet been fixed definitely. If Stallings and Turner did not actually select a lectotype, rigidly construed, certainly the specimen labeled by Dyar as "Co-type (Sensu Restr)" and subsequently figured by Barnes and McDunnough (1912) and again by Stallings and Turner (1954) is the logical choice.
THE NOMENCLATURE OF RESTRICTION
Recognition that Barnes and McDunnough (1912) did, by their published acceptance of Dyar's action, formally restrict aryxna is analogous to the principle accepted by the 1948 International Congress at Paris for the designation of type-species of genera (1950, Bull. Zool. Nomencl. 4:181-2, Conclusion 72). That decision stated in effect that if an author accepted (in publication, of course) a certain species as the type-species on the authority of a previous author or as a result of the supposed operation of some rule, his published acceptance was equivalent to the effective selection of a type-species, even if he was in error as to what the previous author did or what the rule accomplished. In other words, what he accepted and published was effective as of that date, even if not before. By the same reasoning Barnes andMcDuNNOUGH's acceptance and publication of the restriction credited to Dyar should effectively date the restriction from Barnes and McDunnough (1912.)
It seems to me to be essential to stability and universality that we must respect a clear restriction of a mixed species and that subsequent lectotype selection must be in accord with that restriction, and with legitimate successive restrictions, if such were necessary. This principle was recognized by the 1953 Copenhagen Congress in the decision that dealt with neotypes (cf. Copenhagen Decisions, Decision 35 (5) (b). Although the principle is not stated in the decision relating to lectotypes, it is fully as necessary and desirable as for neotype selection, and indeed has been, I believe, the prevailing practice among taxonomists.
1957
The Lepidopterists' Neivs
33
TAXONOMIC PRACTICE
It would be interesting to know how zoologists in general would treat a problem like that of aryxna. I sampled the reactions of a number of colleagues with considerable taxonomic experience and interest in nomenclatural problems. To avoid prejudiced or preconceived opinion, I approached zoologists working in groups other than Lepidoptera, and presented the following hypothetical case which parallels the aryxna description but uses meaningless names:
Smith, 1896, Fauna Beensis: A. flava L. recorded. Jones, 1905: "A. notata, new species
"This is the form figured in the Fauna Beensis, pi. 2, figs. 3 and 4. It differs from flava in having the black areas more extensive, the yellow of the pleura being reduced to rows of spots. I have ten specimens from Quebec from Dr. Jacques and M. Pierre."
Question: What constitutes the original type series? In other words, what specimens are eligible for lectotype selection?
(a) Only the two specimens on which figs. 3 and 4 are based?
(b) Only the ten specimens from Quebec?
(c) All twelve specimens?
Most of those approached asked at once if author Jones actually had before him the specimens on which figs. 3 and 4 were based. In the end, however, on the basis of the original description of "notata", they answered as follows on the composition of the original type series:
All twelve specimens: H. S. Deignan (Aves), D. H. Johnson (Mammalia), C. F. W. Muesebeck (Hymenoptera), R. I. Sailer (Heteroptera), Alan Stone (Diptera), W. W. Wirth (Diptera), and D. A. Young (Homoptera).
The ten specimens from Quebec: W. H. Anderson (Coleoptera), F. M. Bayer (Marine Invertebrata), R. E. Blackwelder (Coleoptera), F. A. Chace, Jr. (Marine Invertebrata), Remington Kellogg (Mammalia), K. V. Krombein (Hymenoptera), P. W. Oman (Homoptera), H. A. Rehder (Mollusca), and L. P. Schultz (Pisces). [Some indicated that they would also include the two figured specimens if it could be shown that author Jones actually saw the specimens].
Conditional, two or ten: H. W. Setzer (Mammalia). (If Jones had the two figured specimens before him, they are the original type series; if he did not, or it it cannot be determined definitely whether he did, then the ten specimens are the original type series).
Two specimens (basis of figures) : None.
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Sabrosky: Megathymus aryxna
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The zoologists sampled clearly placed emphasis on the specimens actually before the author describing the new species. All but one would always include the "ten specimens from Quebec." The group was about equally divided on whether or not to include the two figured specimens in addition to the ten, although several who voted for all twelve indicated reluctance to go beyond the ten that were unquestionably before the author. Most of those voting for all twelve believed that the lectotype should ordinarily be selected from the ten clearly before the author.
CONCLUSION
In consideration of the foregoing discussion, I believe the logical solution in the case of Megathymus aryxna Dyar would recognize as lectotype the male syntype from Arizona that (a) is consistent with the valid restriction by Barnes and McDunnough (1912), (b) bears Dyar/s label "Megathymus aryxna Dyar, Cotype (Sensu Restr)," and (c) was iigured as aryxna by Barnes and McDunnough (1912) and by Stalungs and Turner (1954). The lectotype may be either by designation of the Commission or, if the Commission so interprets, by designation of Stallings and Turner (1954). The specimen referred to is in the collection of the U. S. National Museum.
Literature Cited
Barnes, W., & J. H. McDunnough, 1912. Contrib. Nat. Hist. Lepidop. N. Amer., vol. 1,
no. 3: 56 pp. Bell, E. L., & C. F. dos Passos, 1954. Amer. Mus. Novitates 1700: 1-5. Dyar, H. G., 1905. Jour. N. Y. Ent. Soc. 13: 111-141.
dos Passos, C. F., & E. L. Bell, 1955. Bull. Zool. Nomenclature 11 (9) : 289-294. Skinner, EL, 1906. Ent. News 17: 110-112.
..............., 1911. Trans. Amer. Ent. Soc. 37: 169-209.
Skinner, H., & R. C. Williams, Jr., 1924. Trans. Amer. Ent. Soc. 50: 177-208. Stallings, D. B., & J. R. Turner, 1954. Lepid. News 8: 77-87. _________, 1955. Bull. Zool. Nomenclature 11(9) : 295-296.
Entomology Research Div., Agricultural Research Service, U. S. Dept. of Agriculture, Washington 25, D. C, U. S. A.