Occasional Papers of the Mitscitin of Zoology 3 



The alcoholic material, when received from Mr. Ilirase, 

 was sent to Air. W. F. Clapp of the Museum of Comparative 

 Zoology, Cambridge, Mass., for examination. Unfortunately 

 it was not sufficient in quantity to enable a complete and de- 

 tailed study of the soft anatomy. lUit the results obtained go 

 far towards determining the probable systematic position of 

 the genus. I am indebted to Air. Clai)p for the mounting of 

 the radula figured and the drawings of the soft parts, except 

 Fig. 3. The figure of the radula was drawn by Mr. J. H. Blake 

 of West Somerville, Alass., and those of the shell by Miss 

 Mina L. Winslow of the Museum of Zoology of the Uni- 

 versity of Michigan. 



The radula (fig. 6) has a bicuspid central tooth, six bicuspid 

 laterals, followed by five teeth, intermediate in character, in 

 that the outer cusp gradually diminishes in size and one or 

 more small additional cusps appear, and which gradually 

 merge into the five marginals having a large inner cusp and, 

 progressively, more numerous and small outer cusps ; the bases 

 of all of the teeth are quadrate, being nearly square in the 

 central tooth and widening towards the margin. 



The jaw (fig. 7) is composed of a long, slightly arcuate 

 central plate with two lateral accessory plates. 



The external appearance of the head of the animal is shown 

 by fig. 4 from an adult specimen and fig. 5 from an immature 

 one. 



Mr. Clapp writes in reference to his figures : — 



*' I did succeed, however, in finding what I suppose to be 

 the jaw and enclose a camera lucida sketch (fig. 5) of its 

 position in the animal. In the figure, which is made from 

 above, "a" is the mantle covering the entire animal, thin, deli- 

 cate and transparent, excepting at the outer circumference, 



