228 A, E. Verrill— Mollusca of the New England Coast. 
in 1467 fathoms, two living and three dead (No. 38,209) ; and station 
2096, in 1451 fathoms, one dead (No. 38,211). 
This species has been taken at numerous localities off the European 
coast by the Valorous, Porcupine and other expeditions, and between 
the Azores and Bermudas by the Challenger Expedition; its range 
being from 100 to 1750 fathoms. 
It was also taken in the West Indies and Gulf of Mexico by the 
Blake Expeditions, in 100 to 1002 fathoms, according to Mr. Dall. 
It is also found in the Pliocene of southern Italy. 
The specimens from the Blake Expedition, which I have examined, 
are much more acutely pointed posteriorly, and have much stronger 
concentric striations than our examples. It is quite possible that the 
two forms are not identical. 
Yoldia regularis Verrill, sp. nov. 
Shell small, nearly regularly oval, with both ends obtusely rounded, 
and with the ventral edge broadly and regularly curved. The pos- 
terior end is a little narrower and more tapered than the anterior. 
The posterior dorsal margin is convex and rounded about as much as 
the ventral edge. The anterior dorsal margin is distinctly concave 
in front of the beak, but there is no defined lunule. The umbos are 
somewhat prominent, of moderate size, and curved forward. The 
beak is situated at about the anterior third. The surface is smooth, 
polished and iridescent, without any sculpture except slight and 
irregular lines of growth. Epidermis is thin and yellowish white. 
The hinge-margin is rather strong and curved, the posterior portion 
much longer than the anterior, and bearing about eight rather large 
and stout, prominent teeth. The anterior portion is short and nearly 
straight, and bears four or five prominent, erect teeth, the last tooth 
situated only a short distance from the beak. The cartilage-pit is rel- 
atively large and oblique and extends back a little ways from the 
beak. 
Length, 3°5™" ; height, 2°5™". 
Station 1093, off Martha’s Vineyard, in 349 fathoms, 1882. Three 
specimens (No. 38,420). 
This small species differs from all others recognized from our coast 
in its very regular ovate form, with the beak directed anteriorly, so 
that it resembles externally a minute Tapes or Mactra, or a com- 
pressed species of Callista. It is also remarkable for the shortness 
of the anterior hinge-margin and the small number of anterior teeth, 
as well as for the unusually large cartilage-pit. 
