1890] Recent Literature. ^9^ 



fauna we may as well give a list of them : Tardus auduboni and T. swai'n- 

 sonii are ranked as species, distinct from T. fallasii and 7". us tula t us 

 (both of which are also given) , as are also Vireo cassini and V. flumbcus: 

 Pyranga cooperi is recognized as specifically distinct from P. cestiva; 

 Melospiza montana and M. heermanni are also regarded as species, the 

 latter, bv the way, being not M. heermanni hut M. fasciata mexicana, one 

 of the most strongly marked of the many geographical forms into which 

 M. fasciaia has become differentiated. The same rank is accorded 

 Cardinalis igueus, though the equally distinct form belonging to southeas- 

 tern Mexico (C cardi?ialis coccineus) is referred to C. virginianus,* and to 

 Ckondestes strigatus, although the latter is no more different from C. gram, 

 niacits than Spizella socialis arizonce, Passer cuius sandwickensis alaudinust 

 and Coturniculus passerinus perpallidus are from S. socialis, P. sandwick- 

 ensis and C. passerinus, respectively, these three trinomials being given as 

 mere synonyms of the binomials which follow. The differences between 

 the two forms of Ckondestes are, in fact, of exactly the same character as 

 those which exist between the forms of Spizella, Passcrculus, and 

 Coturniculus, above mentioned ; and if Ckondestes strigatus is recognized 

 as a species, so also should be Spizella arizoua?, Passerculus alaudinus, 

 and Coturniculus perpallidus. But to accord these specific rank would 

 be a violation of our knowledge of their relationships, for every ornitho- 

 logist who has compared large series of specimens knows that they inter- 

 grade completely with their eastern or western representatives along the 

 line where their habitats merge together, just as does Ckondestes gram- 

 macus strigatus with the true C. grammacus. 



Icterus cucullatus nelsoni is given as a distinct species {I. nelsoui), while 

 an equally marked variation, in the opposite direction, from the typical 

 form, I. c. igneus, \ is considered the same as I. cucullatus. 



These instances show clearly how useful, if not indispensable, is the 

 modified form of the binomial system of nomenclature, which has been 

 adopted and, as consistently as possible, followed by the Committee of the 

 American Ornithologists' Union, and not a few of the working ornitholo- 

 gists of Europe as well. 



In other cases, we regret to see forms which, in the light of material 

 contained in collections on this side of the Atlantic, appear to be distinct 

 enough to merit at least subspecific recognition, utterly ignored, except 

 that their names are given in the synonymy. Such as these are the Mex- 

 ican and Guatemalan Bluebirds (Sialia sialis azurea and .S. 5. guatcmala?) , 

 which are called simply 5. sialis; Icteria longicauda {I. virens longicauda 

 of American authors), which is considered a synonym of I. virens, yet is 

 quite as different from the latter as is Pyranga cooperi from P. atstiva; 

 and the following additional but no less conspicuous cases : The several 

 South American forms of Progue which have uniform blue-black males 



*On this subject see 'Proceedings of the United States National Museum,' Vol. 

 VIII, 1885, pp. 569-570. 

 f See 'Proceedings of the United States National Museum,' Vol. VIII, p. 19. 



