DALL: MOLLUSCA AND BRACHIOPODA. 381 
52’ §.), in 348 fathoms, mud, bottom temperature 50° F. U.S. N. Mus. 
96,923. Also at station 2782, in 258 fathoms, mud, temperature, 48° F. 
This pretty little species looks something like the young of Y. thraciaeformis 
(cf. Hanley, Mon. Nuculacea, fig. 4), but is entirely unlike any species reported 
from the region mentioned. 
Yoldie (Yoldiella) indolens Da tt, n. sp. 
Shell small, tumid, translucent, with a dull olivaceous periostracum, smooth 
surface and oval form, except that there is a slight angulation near the posterior 
end of the hinge line; anterior end shorter, rounded, base evenly arcuate; pos- 
terior end slightly compressed and angulated above; interior porcellanous ; 
hinge-line with about a dozen teeth on each side of a deep, small pit for the 
resilium directly under the low beak; pallial sinus distinct but small. Length of 
shell, 5.25 ; of posterior end, 3.25; alt. 3.5; max. diam. 2.25 mm. 
U.S. S. “Albatross,” station 2784, on the southern coast of Chile, in 194 
fathoms, mud, bottom temperature 51°.9 F. U.S. N. Mus. 122,740. Also at 
station 2785, in 122 fathoms, temperature 48° F. 
A comparison of the young of Y. chdlenica of the same size with adults of the 
present species shows that, although of very similar profile, in addition to the 
differences of color and surface Y. chilenica at that age is much less inflated. 
Yoldia (Yoldiella ?) infrequens Datt, n. sp. 
Shell very small, callistaeform, tumid, inequilateral, covered by an olivaceous 
periostracum ; beaks prominent, tumid ; both ends of the shell evenly rounded, 
the posterior not attenuated ; anterior hinge line with about nine, posterior with 
thirteen teeth, separated by a very small pit for the resilium; interior chalky ; 
exterior surface evenly, finely, concentrically striated, the sculpture fainter toward 
the ends of the shell. Length, 4.4; of anterior end, 2.0; alt. 3.5; max. diam. 
2.0 mm. 
U.S. 8. “ Albatross,” station 2784, in 194 fathoms, mud, off the coast of 
southern Chile, bottom temperature 51.°9 F. U.S. N. Mus. 110,692. Also at 
station 2783, in 122 fathoms, mud, temperature 48°. 
A very simple little species which agrees with no other of the region and is 
evidently adult. 
Yoldia (Yoldiella ?) mantana Datt, n. sp. 
Shell small, elongate-oval, white, with a pale yellowish periostracum, nearly 
equilateral, the beaks opisthogyrate, showing the protoconch distinctly ; anterior 
end expanded, evenly rounded; posterior end somewhat attenuated, at the end 
rounded ; surface with a few irregular concentric striae, but mostly smooth and 
