Oil new Mammals from Bolivia. 211 



form of an elliptical projection, and the posterior area is a 

 flat expansion. Both, especially the anterior projection, are 

 quite sensitive to mechanical stimulation. They are both 

 entirely distinct from the organ of special sense described by 

 Brooks (1). Their special functions remain to be deteriniaed. 

 ]\Iy thanks are due to Dr. W. K. Brooks, who has dh-ected 

 this work, and I wish publicly to acknowledge my indebted- 

 ness to my wife, who has materially aided me in securing, 

 tending, and preserving specimens. 



Zoologfical Laboratory, Johns Hopkins University, 

 Baltimore, May I, 1897. 



Literature cited. 



1. Brooks. — " An Organ of Special Sense in the Lamellibranchiate 



Genus Yoldia.'" Proc. Am. Assoc. Adv. Sci. 1874. 



2. Kellogg. — " A Contribution to our Knowledge of Lamellibranchiate 



Mollusks." Bull., U.S. Fish Com. 1890. 



3. KowALEvsKY. — " Etude sur rembryogenie du Dentale." Ann. du 



Musee d'hist. nat. de Marseille, Zool. tome i. 1883. 



4. Lacaze-Duthiers. — " Histoire de I'organisation et du developpe- 



ment du Dentale." Ann. des Sci. nat. iv. S(5r. tome vii. 1857. 



5. MiTSUEiTRi. — ^" On the Structure and Significance of some Aberrant 



Forms of Lamellibranchiate Gills." Quart. Journ. Micr. Sci. 

 vol. xxi. ]881. 



6. Pelsner.— " Contribution a I'etude des Lamellibranches." Archives 



de Biol, tome xi. 1891. 



7. Pruvot. — "Sur le d^veloppement d'un Solenogastre." Comptes 



Rend., Paris, tome cxi. 1890. 



8. Sigerfoos. — " Notes on the Organization of the Larva and the 



Post-larval Development of Ship-worms." Johns Hopkins Uni- 

 versitv Circulars, vol. xv. no. 126. 1896. Ann. & Mag. Nat. 

 Hist. Vol. xviii. 1896. 



9. Wilson. — " Origin of the Mesoblast-bands in Annelids." Journ. of 



Morph. vol. iv. no. 2. 1890. 



XLV. — On some new Mammals from the Neighbourhood of 

 Mount Sahama, Bolivia. By Oldfield Thomas. 



The Briti-sh Museum has purchased from Mr. Gustav Garlepp 

 a small series of mammals obtained by him at Esperanza, a 

 " tambo " in the neiglibourhood of Mount Sahama, Bolivia, 

 while collecting birds for Count von Berlepsch. The speci- 

 mens prove to be of considerable interest, as there are among 

 them examples of no less than five new species, one of these 

 representing a new genus. 



Mr. Garlepp informs me that " the mammals were all 

 taken at an altitude of 4000 metres in the ' Puna ' region — 

 that is to say, on the high plateau between the Coast 



