296 BULLETIN OF THE 
Cuspidaria (?) arcuata Dall. 
Neera arcuata Dall, Bull. M. C. Z., IX. p. 118, 1881. 
Plate III. Figs. 3, 4. 
Habitat. Yucatan Strait, 640 fms. 
As only a single left valve of this species was obtained, it has been imprac- 
ticable to determine to what section it belongs, but the general aspect is that 
of Cuspidaria, or a Halonympha without a clavicle. 
Suscenus CARDIOMYA A. Apams. 
Similar to the preceding, but with radiating sculpture and the fossette more 
vertical and prominent. Type Newra Gouldiana Hinds, 
C. multicostata V. & S., C. perrostrata Dall, and C. ornatissima D’Orbigny 
(+ costata Bush) belong here, as do N. pectinata Cpr. (1865, + var. behring- 
ensis Leche, 1883, from types), and C. californica Dall.* (See Plate III. 
fig. 6.) 
Cuspidaria (Cardiomya) perrostrata Dat. 
Neera (ornatissima D’Orb. var.?) perrostrata Dall, Bull. M. C. Z., IX. p. 110, 1881. 
Neera perrostrata Verrill, Trans. Conn. Acad., V. p. 561, 1882. 
Plate Ii. Figs. 3a, 3b. 
Habitat. Station 43, 339 fms., off Tortugas, bottom temperature 45°.0 F.; 
Station 264, in 416 fms., gray ooze, near Grenada, bottom temperature 42°.5 F. 
Desiring to be as cautious as possible in describing new forms based on very 
little material, I referred to this and D’Orbigny’s C. ornatissima as possibly 
identical, in my preliminary descriptions. That there is a good deal of varia- 
tion in this group is clear, when plenty of material is accessible; but I am the 
more confirmed in the belief that this one is specifically distinct by Professor 
Verrill’s opinion, and by the fact that the Fish Commission has obtained off 
the Carolinas, and Miss Bush has described (as Necera costata), a form which 
seems to be identical with D’Orbigny’s, and is certainly distinct from the 
* Cuspidaria (Cardiomya) californica Dall. Shell differing from C. pectinata by its 
smaller size and proportionally greater length ; larger number of ribs (16-20, while 
pectinata averages 12-14) ; its straighter, longer rostrum with but two strong radi- 
ating lire extending to the lower extreme (pectinata has none, or only several fine 
ones near the body of the valve); its less inflated shape and paler more delicate 
epidermis. Lon. of shell 7.0; of rostrum 2.5; alt. of shell 5.6; diam. 2.75 mm. 
Color yellowish white ; ossicle as usual; buttress present in the right valve. 
Habitat. Catalina Island, California, dredged in 16 fms., mud; Dall, and pre- 
viously Cooper, who confounded it, following Carpenter, with pectinata. 
