Recent Literature. 175 



years, and have themselves visited different portions of the country for 

 this purpose. Besides this they are able to avail themselves of collections 

 received from correspondents and naturalists specially employed in visiting 

 previously unexplored districts. In the elaboration of their work they 

 have called to their aid many eminent specialists to whom have been as- 

 signed all the Vertebrates except the birds, and all the other groups of 

 animals except one division of the Lepidoptcra, as well as the plants. The 

 ornithological portion, which alone demands attention in the present 

 connection, is by the editors, who long since became identified with the 

 ornithology of the region in question. The installments of this portion 

 of the work which have thus far appeared are as follows: Pp. 1-32, pll. 

 i-iii. Sept., 1S79; PP- 33~56j pi- iv, Nov. 1879; pp. 57-S0, pi. v, Feb., 1S80; 

 pp. 81-104, pll. vi, vii, Apr., 1SS0; pp. 105-12S. pi. viii, Aug., 18S0; pp. 

 129-152, pll. ix, x, Febr., 1SS1. The arrangement is that of Sclater and 

 Salvin's ''Nomenclator Avium Neotropicalium," and in the treatment of 

 the subject the authors have advanced as far as the genus Geothlypis. Of 

 each species a short Latin description is given, and all the more important 

 references to the literature are duly cited. The text otherwise relates 

 mainly to the geographical distribution of the species, which is treated 

 with great fullness, with, as occasion requires, remarks on their affinities and 

 nomenclature. There are. however, here and there brief references to 

 their habits. The ten plates thus far published contain figures of 25 hith- 

 erto unfigured species. 



The work very naturally embraces a large number of North American 

 species, which occur either as winter migrants into Mexico and Central 

 America or whose range extends southward beyond our borders ; of the 

 130 species thus far treated just one-half occur north of Mexico. The 

 authors are, of course, rigidly orthodox in respect to nomenclature, 

 adhering strict] j' to the binomial system, although in their text they speak 

 of this or that binomially named form as a "race" of some other similarly 

 designated form. To illustrate : all of our Thrushes of the Hylocichla group 

 are treated as species, Turdus swainsoni, T. ustulatits, T. alicite, T. audu- 

 boni, etc., all being accorded specific rank, while T. ustulatus is spoken 

 of in the text as a "western race of T. stuainsoni." Sitta aculcata, Cer- 

 tliia mextcana, Thryothorus berlandieri, T. bairdi,* etc., are also recog- 

 nized as species, while such forms as Catkcrpes mexicanus conspersus, Cis- 

 tothorus palustris paludicola, Dendrceca dominica albilora, etc., are wholly 

 denied recognition. In short, the geographical varieties or races, now 

 usually treated as subspecies by American writers and designated by a 

 trinomial name, are, with few exceptions, raised to the full rank of species, 

 while those not so recognized are ignored as not requiring special desig- 

 nation. There is apparent, however, a misunderstanding on the part of our 

 authors as to what American writers mean by a race, as is evident in 

 comments at sundry points, as, e. g:. under Dendrcrca dominica, where, 

 speaking of Mr. Ridgwav's race albilora, they say: "The difference at 



* Thryothorus bairdi = Thryothorus bewicki var. leucogaste^ Baird (nee Gould). 



