No. i.] Allen on Mexican Mammals. 187 



These specimens seem to be indistinguishable from De Saus- 

 sure's types of his Hesperomys toltecus, from the " Cordiliere de la 

 province de Vera Cruz," which, through the kindness of Dr. C. 

 Hart Merriam, I have had an opportunity to examine. 



37. Sigiiiodon fulviventer Allen. One specimen, Zacatecas. 

 (See this Bulletin, II, p. 180.) 



38. Hesperomys leucopus sonoriensis (Le Conte). See this 

 Bulletin, II, p. 180. 



39. Hesperomys aztecus De Saussure. Two specimens, 

 Jalisco. (See this Bulletin, II, p. 179.) 



A comparison of these two specimens (shown by the skulls to 

 be not fully mature) with two of De Saussure's three original speci- 

 mens of this species, shows their former reference to H. aztecus to 

 have been correctly made. They are a little smaller than De 

 Saussure's specimens, but agree with them almost exactly in color 

 and in all external details. 



40. Hesperomys melanophrys Coues. 



Hesperomys mexicanus ALLEN, Bull. Am. Mus. Nat. Hist., II, p. 179 (not 

 H. mexicanus De Saussure). 



The single specimen, from Zacatecas, formerly reported (1. c.), 

 has since been compared with De Saussure's type of H. mexicanus 

 and found to be very different. On the other hand, it agrees well 

 with the type of Coues's H. melanophrys^ to which species it is 

 now referred. H. mexicanus and H. melanophrys prove on com- 

 parison to be very different species. 



41. Hesperomys (Nyctomys) sumichrasti De 



specimens, three adult males, one adult female, and one immature 

 female, Santo Domingo, Tehuantepec, April 24 to May i, 1890. 

 The young specimen differs from the adults in being yellowish 

 ashy above instead of golden cinnamon. 



These specimens have been compared with De Saussure's types 

 (see above, p. 175), with which they strictly agree. 



42. Oryzomys COuesi (Alston). One specimen, adult male, 

 Hacienda San Marcos, Tonila, Jalisco, Dec. 30, 1889. 



BJ 



OF THE 



UNIVERSITY 



OF 



