Marine Shells of Massachusetts. 333 
valve one erect, very prominent cardinal tooth ; ante- 
rior muscular impression round-ovate, Doskiriól one 
elongate ; pallial —— with avery large pos- 
terior sinus. 
Length, .62. inch ; pr 38 inch; width, .21 
inch. Of some Lace valves in the cabinet of Mr. 
Shiverick, length, :8 inch ; height, .45 inch. 
Cabinets of Bost. Soc. Nat. Hist. ; of Middlebury 
College; of Mr. Shiverick, of New Bedford ; and my 
own. 
Habitat and station. “This species ithabilé- soft 
mud, in deep water, in harbours, and has been obtain- 
ed only by dredging. It has been found in New 
Bedford and Dartmouth harbours. inhabits " coast 
of S. Carolina: Dr. Ravenel. 
Remarks. A single living specimen was found in 
the summer of 1838, and during the autumn of 1839 
numerous single valves were found in mud dredged 
in New Bedford harbour. Mr. Shiverick has also 
found a living specimen. 
The faint radiating lines of the interior sometimes 
appear very indistinctly on the outside. T. intastri-_ 
ata, Say, differs in having the posterior margin 
rounded, being without lateral teeth, and is of much 
greater size (2.06 inches by 1.6 inch), while, among 
$ 
s hundreds of single valves of this shell, none exceed- 
=- ed the size given.* 5 
* After writing the above Seman, Dr. Gould kindly favored me 
with the loan of No. VIII. of Say’s “ American Conchology,” in whic 
this species is described and hiik That Number is so rarely seen, 
that a description in this Journal cannot be superfluous. 
p 
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