186 FRANCIS HEMMING 



Papilio cressida Fabricius, 1775. Nomenclatorially (though not taxonomically) Boisduval was 

 in error, for, as has been shown in the note on the name Cressida Swainson, the type-species 

 of that genus is the nominal species Cressida heliconides Swainson, but the taxon represented 

 by that nominal species is considered on taxonomic grounds to be the same as that represented 

 by the nominal species Papilio cressida Fabricius. 



Boisduval did not cite the nominal species Cressida heliconides Swainson, when establishing 

 the genus Eurycus, but, as Eurycus was introduced as a replacement for Cressida, it automatic- 

 ally takes as its type-species the nominal species which is the type-species of the genus bearing 

 the replaced name. 



EURYGONA Boisduval, [1836], (Roret's Suite a Buffon), Hist. nal. Ins., Consid. gen., 1 

 (Lepid.) : pi. 3 [= pi. 3 A], fig. 2; pi. 21 [= pi. 5 C], fig. 3. Type-species by selection by 

 Scudder (1875, Proc. amer. Acad. Arts Sci., Boston, 10 : 175) : Eurygona phoedica Bois- 

 duval, [1836], ibid., Consid. gen., 1 (Lepid.) : pi. 21 [= pi. 5 C], fig. 3. 



EURYLAIS Boisduval, 1861, Ann. Soc. ent. Fr. (4) 1, Bull. : xxxix. 



This generic name is a nomen nudum and accordingly possesses no status in zoological 

 nomenclature. It is included here, only because references to it have occasionally been made 

 in the literature. The history of this name is as set out below. 



The name Eurylais in the combination Eurylais daphnis was included in a list of names stated 

 to have been attached to specimens taken by Lorquin in the Philippines and exhibited at a 

 meeting of the Entomological Society of France held on 23rd October 1861 ; it was stated in this 

 report that these names would be included in a forthcoming paper of Boisduval's in the Annals 

 of the Society. This expectation was not realized and these names never acquired status in 

 zoological nomenclature. 



In 1886 (Reis. Philipp. 5 (Schmett. Philipp.), Ins., Rhop. 1 : 7 nota 1) Semper discussed the 

 question of the identity of the taxon which Boisduval had intended to name Eurylais daphnis, 

 and concluded that it was that to which in 1861 (Wien. ent. Monats. 5 : 300) Felder (C.) had 

 given the name Danais anapis, which later became the type-species of Aianthis Fruhstorfer, 

 [1910]. It may reasonably be inferred that Boisduval realized that the taxon Danais anapis 

 named by Felder in the same year as that in which he had exhibited Lorquin's collection 

 from the Phillippines was the same as that which, at the time when he made that exhibit, he 

 intended to call by the name Eurylais daphnis and that it was for this reason that he abandoned 

 his plan to publish that binomen. 



EURYMUS Horsfield, [1829], Descr. Cat. lep. Ins. Mus. East India Coy (2) : 134. Type-species 

 by original designation : Papilio hyale Linnaeus, 1758, Syst. Nat. (ed. 10) 1 : 469. 



When it was realized that under the Code the type-species of the genus Colias Fabricius, 

 1807, was Papilio rhamni Linnaeus, 1758, and therefore that that generic name could not be 

 used any longer for Papilio hyale Linnaeus and the other " Clouded Yellows " (the 

 " Sulphurs "), the name Eurymus Horsfield was adopted by those specialists — a minority 

 only — who decided to abandon the use of the name Colias for this group. The reluctance to 

 give up the name Colias for this group and instead to use it for the " Brimstones " in place of 

 the name Gonepteryx Leach was so strong that ultimately the Commission was asked to use its 

 Plenary Powers to designate Papilio hyale as the type-species. As has been explained in the 

 note under the name Colias, this request was approved by the Commission by its Opinion 146 

 published in 1943. Thereupon, the name Eurymus Horsfield became a junior objective syno- 

 nym of Colias Fabricius, 1807. 



For quite another reason, and one which had been overlooked by those specialists who at 

 one time used the name Eurymus Horsfield for Papilio hyale and its allies, that generic name 

 was — and always had been — invalid, for it was a junior homonym of the name Eurymus 

 Rafinesque, 1815 {Analyse Nature : 117). 



Horsfield stated that the name Eurymus was a manuscript name of Swainson's ; two years 

 after the appearance of Horsfield's Catalogue, it was actually published by Swainson (1831, 

 Zool. Illustr. (2) 2 (13) : pi. 60). 



