1894.] NATURAL SCIENCES OF PHILADELPHIA. 243 



a total mi.'^apprehension of my meaning, for instead of speaking of 

 the color of the teeth themselves he refers to the dirty coating on the 

 outside of the teeth. He says: "The black coloring consists to a 

 large extent of a superticial incrustation which tends to scale off in 

 flakes in the prepared skull, and its absence apparently may be due 

 sometimes to removal in the process of cleaning the skull for the 

 caliinet. In other words, the blackness is to some extent an acci- 

 dental or pathological condition, due probably more or less to the 

 particular character of the food or to the health of the animal." 

 But for this perverse interpretation of my very plain statement it 

 would not be necessary to explain that when I said "color of teeth 

 white or nearly white" I meant the teeth — the osteodentine and en- 

 amel — not the dirty deposit that sometimes collects on the outside of 

 the teeth. But after all, the peculiarity is one of little consequence 

 and was only mentioned by me after enumerating the characters by 

 which members of the leacodon'"^ group may be distinguished from 

 others. 



The following list of the 22 species and 10 subspecies recognized 

 by me contains under each name: (1) reference to the original de- 

 scription; (2) the principal synonymy; (.■>) the type locality; (4) the 

 known geographic distribution. 



Descripti(jns of the species are not added because they are included 

 in a more formal and fully illustrated revision of the genus which 

 will he published later. 



Neotoma leucodon .Mcriiam. 



ycoloiiia h'ltcndon Morriaiu, Proc Biol. Soc. Wash., IX, .Tuly :.', lsi)4, 120. 121. 



Type loculitij : San Luis Poto.si, Mexico. 



Geoijraphir distribution. — Upper part of Lower Sonoran Zone in 

 Central ^Mexico, from Berriozabal, Zacatecas, easterly to southern 

 San Luis Potosi, and tlience southeast to Perote, Vera Cruz. 



Neotoma latifrons ^Mciriam. 



.Wotuiiia la/ifroiis .Mcrriaiii. Proc. P>iol. Soc. Wasli., IX, .July 2, l,S!t4. 121. 



Type bmditij : Querendaro, ^lichoacan, Mexico. 

 Getx/raphic distrihidion. — Valley of Querendaro, south side of 

 Lake Cuitzeo, Michoacau, Mexico (range unknown.) 



"^ Named, as stated, after -^'. lcucudo)i, a central member of the group, not 

 because all the species have white teeth. 



