A, EF. Verrill—Mollusca of the New England Coast. 445 
short-triangular, subacute, with a shallow concave notch. The liga- 
ment-pit is small and triangular. The hinge-margin is thin and 
simple. Beaks small, rising slightly above the margin in the left 
valve, and not quite reaching the margin in the right valve. The 
anterior margin of the shell projects considerably forward in a broad 
curve; the ventral margin is broadly and regularly arched, but pro- 
jects downward a little more strongly behind the middle; the poste- 
rior margin is much less convex than the anterior, and in its upper 
part somewhat straightened. The concentric undulations of the sur- 
face are broad and regular, the depressions about equal to the undu- 
lations ; they become much broader in proportion as they recede 
from the umbos, the last four occupying about one-half the breadth of 
the shell. The radiating lines are very thin, but distinctly elevated 
and roughened, or rendered slightly irregular by the very fine micro- 
scopic lines of growth, which everywhere cover the shell. The radiat- 
ing lines are readily visible without a lens. Color translucent bluish 
white. 
Length, 19™™; height, 20™™; breadth, 5™™. 
The single living specimen was taken at station 2229, in 1,423 
fathoms, N. lat. 37° 38’ 40”, W. long. 73° 16’ 30", (No. 44,827); a 
fragment occurred at station 2221, in 1,525 fathoms (No. 44,828.) 
BRACHIOPODA. 
Atretia gnomon Jeffreys. 
Ann. Mag. Nat. Hist., Sept., 1876, p. 251; Proc. Zool. Soc. London, for 1878, p. 
412, pl. 23, fig. 4. 
Verrill, Trans., Conn. Acad., vol. vi, p. 234, 1884. 
This species was included in my preceding catalogue as one of 
those which had been taken off the coast of Labrador (Valorous 
Exp.), but not from off the coast of the United States. In 1884, 
however, it was taken in large numbers at station 2221, N. lat. 39° 
05’ 30”, W. long. 70° 44’ 30", in 1,525 fathoms. (two hundred and 
twenty-five specimens, mostly living.) A few specimens also occurred 
at the adjacent station, 2222, in 1,537 fathoms; and a single living 
specimen was taken at station 2174, N. lat. 38° 15’, W. long. 72° 03’, 
in 1,594 fathoms. 
These specimens agree perfectly with north European specimens 
sent by Dr. Friele. 
