446 MR. E. R. ALSTON ON A NEW SHREW. [May 15, 



Molars with the usual W pattern towards the outer edge and broad 

 low inner portion, which in the second and third rises into a distinct 

 cusp. 



Jig.3. 



Fig-. 2 

 Skull and dentition of Sorex vera-^acis. 



The lower incisor is long and stout, with one well-marked and one 

 nearly obsolete internal cusp. The canine is small and simple ; and 

 the premolar and molars have each one inner and two outer cusps. 



Hab. Cohan (Vera Paz), Guatemala {Brit. Mus.). 



I may here observe that the Shrew named Corsira tropicalis by 

 Gray, at the same time as the above, seems to be the same as that 

 subsequently described as Sorex micrurus by Mr. Tomes\ Dr. 

 Coues informs me that it proves to belong to the division of Blarina, 

 which have thirty-two teeth ; but whether it is distinct from some of 

 the described North- American species remains to be ascertained. 



These Central-American Shrews are interesting as showing how 

 far the Insectivora have penetrated into the Neotropical Region, 

 their further advance having doubtless been checked by the com- 

 petition of the smaller Edentates and Marsupials. 



As all the Guatemalan Mammals named without description by 

 Gray in the Society's 'Proceedings' for 1843 (p, 79) have now been 

 determined, I add a list with their synonyms : — 



1. Heteromys desmarestianus^ H . desmarestianus, Gray, P. Z. S. 

 1868, p. 204. 



2. Corsira tropicalis = Blarina micrura (Tomes) : cf. supra. 



3. Corsira temlyas = Sorex verce-pacis, Alston : cf. suiira. 



4. Saccophorus guochil = Geomys hispidus, Leconte : cf. Coues, 

 Proc. Acad. Philad. 1875, p. 133. 



5. Mus tazamaca = Ocketodon mexicana (De Sauss.) : cf. 

 Alston, P.Z.S. 1876, p. 756. 



6. Mus teguina = Hesperomys teguina, Alston, P. Z. S. 1876, 

 p. 755. 



1 P.Z.S. 1861, p. 279. 



