Vol. XX, pp. 75-80 July 22, 1907 



PROCEEDINGS 



f)F THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTIONS OF TEN NEW KANGAROO RATS. 

 BY C. HART MERRIAM. 



The collections of the Biological Survey contain ten appar- 

 ently undescribed species and subspecies of kangaroo rats from 

 California and JNIexico — the latter collected by E. W. Nelson and 

 E. A. Goldman, mainly in the course of their recent explora- 

 tions on the peninsula of Lower California. Of the 10 new 

 forms, belong to the genus Dlpodomys and 4 to the genus 

 Perodipus. 



In working out the ranges of the various species of the group 

 I am indebted to Mr. E. A. Goldman for helpful assistance. 



Following are descriptions of the new forms: 



Dipodomys spectabilis cratodon nubsp. iiov. 



Type from C'liicalnlc, Aguas Culicntes, Mexico. No. 78,953 d^ ad., 

 U. S. National Museum, BioIo.eical i^urvey Collectiou. Collected July 2, 

 ISiHi, by P:. W. Nelson and E. A. (Toldman. Orig. No. 97:U. 



Characters. — Similar in general to spectafrilig Init skull larger — largest 

 of the genus — more massive, deeper wrtieally, with broadtT rostrum and 

 premaxilhe, narrower interparietal area, an<l )inir}i hruader and heavier 

 incifiors. 



Mea.^uremenls. — Type specimen ( c? ad.): total length, :U2; tail ver- 

 tebra% lM7; hind foot, ■'A. Average of 9 from type locality: total length, 

 337; tail vertehne, 20S; hind foot, 52.."). 



Dipodomys nelsoni sp. nov. 



Ti/pe from La Ventura, Coahuila, Mexico. No. 79,439, c? ad., U. S. 

 National jNIuseum, Biological Purvey C(jllection. Collected Aug. 10, ]S9(). 

 Nelson and tioldman. Original No. 9998. 



Range. — From Santa Rosalia, C'hihuahua, to .Taral and La ^\'ntura, 

 Coahuila, and thence to Dr. Arroyo, Nuevo Leon. 



('Jiarach'i's. — Much smalk'r than i^jieetahllis and very much larger than 

 p]i III i psi gronyi. (41 x 27 skull. ) Similar to apectahlUa in general form 

 and massiveness of skull but nnich smaller. 



Mastoids large; interparietal area small; mastoi<ls actually nearly as 

 large — relatively larger — than in s^iteetabUls; zygomata not so squarely or 

 17— Proc. Biol. Soc. W.vsh., Vol. XX, 1907. {'ib) 



