612 Dr. A. Anibiick-CIiiistie-Lincle o)i the 



shown below — the possibility of the existence of an upper 

 one in younger specimens is not excluded, though it is 

 suppressed in older stages. 



I therefore regard the following teeth as premolars, and 

 have designated them P\ P^, P^. The first two are repre- 

 sented by large buds, the last one is much in advance and is 

 bell-shaped. 



I will call attention to my notation of the premolars being 

 a provisional one. P* in Neomys is in all probability the 

 homologue of P* in Sorex, and the teeth called P^ are 

 probably homologous structures in the two animals. But 

 the material at my disposal does not enable me to decide 

 whether P- or P^ in Neomys is suppressed. It seems to me 

 most probable that it is P- that remains and P^ that is 

 suppressed. 



This view is based on the fact that in shrews having the 

 full set of premolars P^ is generally of varying size and some- 

 times so highly reduced that it has hardly cut the gums. I 

 refer to the excellent figures of several species of Sorex and 

 Blarina — e. g. /S. personatus, S. fumeus, S. merriami, S. lonyi- 

 rostris; B. brevicauda, B. tehnulestes, B. caroVmensis — which 

 we owe to Merriam * and Miller f. One might therefore be 

 inclined to suppose that the final result of the reduction of 

 P^ may be the total suppression of this tooth in some species. 



If it is allowed to presume that the tooth development is 

 the same in different genera of the Soricidre, it is thus P^ 

 that has been reduced in Neomys. But of course only an 

 ontogenetic investigation of younger specimens will make a 

 decisive, conclusion possible. 



M^ is in advance of the other two molars, being bell- 

 shaped; the free deep end forms a lingual swelling. ^P is 

 about to become bell-shaped and j\P is represented by a large 

 swelling of the end of the tooth-band. 



The lower jaw. 



The tooth-band is not continuous ; it is divided into two 

 halves. 



The germ of I^ — the functional first incisor, whicli is 

 designated in the same way as the corresponding tooth in 



* Merriam, C. Hart, " Revit^iou of the Shrews of the American Genera 

 Blarina and A^'otiosorex,'^ " Synopsis of tlie American Shrews of the 

 Genus Sorex," North American Fauna, no. 10 (Washington, 1895). 



t Miller, Gerrit S., .Jan., "The Long-tailed Shrews of the Kastcru 

 United States," North American Fauna, no. 10 (Washington, lS9o). 



