DALL: MOLLUSCA AND BRACHIOPODA. 395 
mud, bottom temperature 46°.9 F. U.S. N. Mus. 118,241; and station 2783, 
in 122 fathoms, mud, temperature 45°. 
This species, agreeing exactly with the figure in the report of the Mission to 
Cape Horn, above cited, has a pale brownish periostracum with rather short hairs, 
prominent though small beaks, and smooth flat valve-margins. The periostracum 
is less adherent than usual in this genus and often has dropped off entirely in 
comparatively fresh specimens. The hairs are much longer in the young than in 
the average adult. The area is very narrow; the ligament occupies a very narrow, 
lozenge-shaped area about equally in front and behind the beaks ; the resilium is 
central, forming a minute triangle in each valve, and the depression in the amphi- 
detic area to receive it is very shallow and sometimes, ina slightly eroded valve, 
imperceptible, which accounts for the error already alluded to. Another error, 
probably typographical, occurs in printing the measurements, as will be seen on 
comparmg them with the figure. The average measurements are: length, 26; 
height, 24; diam. 9 mm., exclusive of the periostracum. 
The sculpture consists of feeble, irregular incremental lines and obsolete numer- 
ous, rather distant radial striae, out of which the hairs grow, the interspaces being 
quite flat, and the striae, broken by the lines of growth, have here and there a 
faintly punctate aspect. There are ten anterior and about the same number of 
posterior teeth, sometimes forming a continuous arch, but usually with a faint 
medial depression, more conspicuous in the young shells. 
Nothing corresponding to the unfigured Z. hirtella Mabille ct Rochebrune, 
from Orange Harbor, was discovered in the ‘‘ Albatross ” collections. 
(B. Wit crRENULATE Mareains.) 
Limopsis diegensis Datt, n. sp. 
Plate 15, figures 13, 15. 
This small, oblique-ovate, and rather swollen species is light brown, rather 
sparsely pilose, thin, with a small resilium, about seven anterior and four to five 
posterior hinge teeth, which are small and delicate, the two series separated by a 
short edentulous gap. When the periostracum is removed, the sculpture is not 
unlike that of Z. jousseaumi, but more emphatic, and the radii are distinctly punc- 
tate. The interior is faintly grooved and the ventral margin distinctly crenulate, 
or rather beaded. 
Of San Diego, in 80 fathoms, F. W. Kelsey; U.S. 8. “Albatross,” station 
9923, in 822 fathoms, mud, off San Diego, California, bottom temperature 39° F. 
U. S. N. Mus. 122,585. 
Limopsis mabilliana Dat1, n. sp. 
Shell small, subquadrate, with pale brown periostracum sparsely arranged along 
the radial and concentric sculpture so as to form a fringed reticulum, the hairs 
