318 Marine Shells of Massachusetts. 
the results of ‘an analysis of the mineral now making 
by my friend Mr. Hayes, whose accuracy in this 
department of science is well known to the members 
. of this Society, as well as to the friends of science. 
— s 
ART. VIII. — DESCRIPTIONS OF THIRTEEN NEW SPE, 
CIES OF NEW ENGLAND SHELLS. By C. B. Apans, 
Member of the Bost. Soc. Nat. Hist, Prof. Chem. and Nat. Hist. 
-in Middlebury College, Vt. 
Tue marine species of shells, which are sf iss 
in the following article, have. been found only in 
New Bedford and its edd vicinity. They are 
rarely obtained, even by dredging. From their sta- 
tion and their rarity, they have hitherto eluded obser- 
vation. In my examination relating to them, I have 
been much indebted to Mr. C. F. Shiverick, of New 
Bedford, whose persevering and close observation, has 
contemporaneously or subsequently to my own re- 
. Searches, secured most of the specimens which have 
been distributed. To the same gentleman I am also 
indebted for the discovery of three of the fresh-water 
species. To my friend, Dr. A. A. Gould, I am much 
indebted, especially for the BERE of all the nouit 
described. — 
Prsenorón PLICATA. 
Plate HT. Fig. 6. 
E testà parva, crassa, rae a albido-fuscâ, stiis et pir 
decussatà ; epidermide tenni; anfractibus sex; suturà valdé impres- 
si; aperturà ovatà ; labro areuato, sinu -- cauda brevi; columel- 
là acuta. 
