454 SHIMER. 



Odosiomia fusca. — The specimens from Exeter Street are small, 

 averaging 3 mm. in length. 



TtirboniUa winJcleyi. — An average specimen from Exeter Street 

 measured 5 mm. long by 1.5 mm. wide at the large whorl. Its propor- 

 tionate length and breadth are the same as those of some recent forms 

 from Buzzards Bay. 



LiUonna rudis. — The Exeter Street forms are small; the largest is 

 9 mm. long. A normal young individual 10 mm. long was noted 

 from Muddy River. 



Littorina rudis tenebrosa. — The Exeter Street forms are small ; 

 the largest is 5 mm. long; two specimens retain the peculiar mottled 

 checking so characteristic of this variety. 



Littorina paUiata. — Two specimens were noted from Exeter Street, 

 the larger of which has a length of 9 mm. and a width of 8 mm. 



Crepidula fornicaia. — The Exeter Street specimens of this, the com- 

 mon Decker, vary from tliin to heavy; are whitish without and within 

 and moderately convex, with white platform. The shells noted are 

 small; one has a length of 14 mm., a breadth of 11 mm., a height of 4 

 mm. with a depth of platform of 2 mm. Those from Berkeley Street 

 and City Point are normal both in size and shape. 



Crepidula plana. — Very probably this Flat Decker form is C. 

 fornicata modified by its position. The Exeter Street shells are thin, 

 white without and within, and flat, with white platform. The shells 

 noted are small; one has length 10 mm., breadth 8 mm., height 1.5 

 mm., with depth of platform .2 mm. The Berkeley Street specimens 

 are of normal size. Only two specimens were noted from City Point, 

 the larger one of which had a length of 25 mm. 



Crepidula convexa. — The Exeter Street specimens of the Convex 

 Decker are small and very conve~x. The color outside is ashen brown, 

 within reddish brown; the deeply seated platform is similar in color 

 to the inside of the shell in very young (4 mm. long) specimens, lighter 

 brown in older (11 mm. long) ones. One specimen has length 11 mm., 

 breadth 8 mm., height 5 mm., depth of platform 2.5 mm. Another 

 has length, 4 mm., breadth, 3 mm., height, 2 mm., depth of platform, 

 1 mm. 



Poliniccs heros. — (Polinices is Montfort's original (1810) spelling 

 of the genus.) The Muddy River specimens average 19 mm. in 

 length by 17 mm. in width. From City Point two specimens were 

 noted, considerably larger than those from ]\Iuddy River. 



Polinices triseriata. — The single specimen notetl from Muddy 

 River was small but well preserved. Those from City Point had an 

 average length of 23 mm. 



