304 BULLETIN OF THE 
Myonera undata VeRRILL. 
Neera undata Verrill, Trans. Conn. Acad. Sci., VI. pp. 223, 277, June, 1884. 
Habitat. Off Chesapeake Bay in 2221 fms. (Verrill); fragments were ob- 
tained by the “Blake” in 450 fms. near Havana; at Station 175, near 
Dominica, in 611 fms., ooze, bottom temperature 40°.0 F.; and at Station 230, 
near St. Vincent, in 464 fms., bottom temperature 41°.5 F. 
This species must attain a considerable size and remain extremely fragile. 
The pieces obtained by the “ Blake” indicate its place to be with Myonera, 
but there is no buttress or appearance of an internal rib. 
Myonera lamellifera Datt. 
Neera lamellifera Dall, Bull. M. C. Z., IX. p. 113, 1881. 
Plate ITI. Fig. 7. 
Habitat. Station 36, 84 fms.; a single right valve. 
A comparison of figures will show that Mr. Smith’s Newra consociata is 
wholly distinct from this species. N. semistrigosa Jeffreys, is less oblique in 
form, and the concentric ruge are mere threads, not rising clear and sharp 
from the shell as in M. lamellifera. Moreover they belong to entirely different 
groups, semistrigosa being a typical Cuspidaria. The present species has a faint 
rib leading to an obsolete buttress, but no teeth, while the fossette lies poste- 
riorly directed in a narrow groove on the hinge margin. 
Its nearest relative seems to be the next species. 
Myonera limatula Dati. 
Neera limatula Dall, Bull. M. C. Z., IX. p. 112, 1881. 
Neera contracta Jeffreys, P. Z. S., 1881, p. 941, pl. Ixxi. fig. 4, 1882. 
Plate III. Fig. 5. 
Habitat. Station 44, 539 fms., off Tortugas; bottom temperature 39°.5 F. 
Two perfect and two broken valves. 
None of the specimens of Newra contracta in the Jeffreys collection at 
Washington show any tooth whatever in either valve. The posterior cardinal 
margin of the right valve is bevelled off a little, to fit in under the edge of the 
left valve, but it is not a tooth in any ordinary sense. 
It differs from the preceding species in its smaller size with equal length, 
finer and less elevated sculpture, and less evident posterior ventral sulcus. In 
one right valve there is a point extending forward and downward from under- 
neath the middle posterior hinge-line, but this seems clearly pathological. 
There is no buttress or rib internally. 
