anteriorly (Fig. 7 B) and, at times, elongate with rounded anterior 

 margin and sharply expanded sides (Fig. 7 C). On the right 

 side a collar arises surrounding the head, on the left a hood from 

 which the eggs arise. The eggs are in clusters numbering seven. 

 (Fig. 7 B). These clusters surround the head. The young shell 

 (Fig. 7 A) resembles the shell of Velutina laevigata as noted by Jeffreys. 

 The creature devoured greedily fragments of Yoldia limatula and 

 when teased with a scalpel snapped at it in a vicious manner. 



CEMORIA NOACHINA Linn 

 PI. II. Fig. 8. Length 5 mm. 



The figure of this species in Forbes and Hanley under the name 

 of Pundurella noachina shows some differences from our species. 

 The shell is represented as standing much lower, the foot hardly clears 

 the lower margin of the shell. The head tentacles are represented as 

 much longer and pointed, the lateral tentacles are seven in number 

 increasing slightly in length to the last one, while in our species the 

 next to the last one is twice the length of the others. The foot is much 

 narrower in our species and the edge is sharply indented and irregular. 

 (PI. II. Fig. 8 A). Jeffreys figures the Enghsh species with ten 

 lateral tentacles on a side, the penultimate one larger than the rest. 

 These differences may be regarded as varietal only. 



In the early stage of Cemoria (PI. VIII Fig. 8,) the shell resembles 

 a Sigaretus and then suddenly appears the close rib-like growth of 

 the adult form. The growth is much more rapid anteriorly so that 

 the nepionic shell stands almost vertical in relation to the marginal 

 line. 



MARGARITA UNDULATA Sowerby 

 PL II. Fig. 9. Diameter 11 mm. 



This species is undoubtedly the Trochus groenlandica of Chem- 

 nitz, as given by Johnson in his list of the Mollusca of New England, 

 but, following Gould, I retain the old name. Forbes and Hanley 

 quoting Alder, say that the animal is white or yellowish white, also, 



