on the Genus Scalops. 27 



Shrews (Sorex), and Pennant among the Moles {Talpa). 

 Baron Cuvier finally established for it a new genus (Scalops), 

 where it still remains. The specimen, however, which he 

 made the type of the genus, contained but thirty teeth. The 

 upper jaw had but three lateral incisors, or false molars, on 

 each side, leaving considerable intermediate spaces between 

 the incisors and true molars. In this dental arrangement he 

 was followed by Desmerest, Dr. Harlan, Griffith, and nearly 

 all the naturalists of that period. Subsequently, however, 

 Fred. Cuvier gave a correct description of the teeth, which 

 he found amounted to thirtysix. Dr. Harlan, finding a skele- 

 ton from the vicinity of Philadelphia, which, in its dental 

 arrangement, corresponded generally with the characters given 

 by Fred. Cuvier, considered it a new species, and described it 

 under the name of Scalops Pennsylvanica^ (see Fauna 

 Americana, p. 33). Finally, Dr. Richardson described a spe- 

 cimen which was obtained on the Columbia River, which 

 contained fortyfour teeth, very difierently arranged. This 

 animal he refers to the S. Canadensis, {aquaticus, of Lin- 

 naeus,) supposing that the difference in the dentition, as 

 observed by different authors, was owing to their having ex- 

 amined and described speciinens of different ages. (See 

 Fauna Boreali-Americana, p. 82). I will endeavor to explain 

 and correct these contradictory views. 



The specimens examined by Baron Cuvier, Desmarest, and 

 Dr. Harlan, were evidently young animals, with their denti- 

 tion incomplete. One half of the specimens now lying be- 

 fore me, present the same deficiency in the number of teeth— 

 also the edentate spaces between the incisors and grinders, 

 remarked by those authors. Those, on the other hand, that 

 were examined by Frederick Cuvier, Dr. Godman, and the 

 skeleton of Dr. Harlan's Scalops Pennsylvanica, were the 

 adults of the same species ; and the description of Dr. Rich- 

 ardson's specimen was that of a new species. (See Journal 

 Acad. Nat. Sciences, Vol. YHI. p. 5S.) I have been obliged 

 to make a slight alteration in the generic characters to admit 

 the species which have since been discovered. 



