DALL: MOLLUSCA AND BRACHIOPODA. 295 
lip with a thin callous coat of enamel, continuous with the outer margins; pillar 
short, axis imperforate, with two strong oblique plaits near the proximal end of 
the pillar ; canal obsolete. Length of shell, 21.5 (to 26.0); of last whorl, 16.0; 
of aperture, 10.5; max. diam. 9.5 mm. 
U.S. S. “Albatross,” station 2936, off San Diego, California, in 359 fathoms, 
mud, bottom temperature 49° F. Also at station 4382, in 656 fathoms, mud, 
temperature 42°.5; at station 4407, off Catalina Island, in 600 fathoms, sand, 
temperature 39°.4; and station 4425, in 1100 fathoms, mud, north of San Nicolas 
Island. 
The figure of this pretty species was drawn from a rather small specimen. The 
type of the Merica group is Cancellaria melanostoma Sowerby. 
Cancellaria (Merica) centrota Datt. 
Plate 1, figure 8. 
Cancellaria centrota Dall, Proc. U. S. Nat. Mus., 1896, 18, p. 13. 
Shell solid, short, ashy or pinkish white, with a smooth, small nucleus of two 
whorls, and five and a half strongly sculptured subsequent whorls; spire sub- 
tabulate, rather pointed; sculpture of five or six strong spiral threads, of which 
that at the shoulder is much the largest, crossed by (on the last whorl nine) sharp, 
recurved varices, spiny at the intersections in well-developed specimens, the spines 
at the shoulder much longer than the others, while in some depauperate specimens 
the only spines are at the shoulder; there is also some obscure spiral striation 
between the threads on the last whorl, and the lines of growth are irregular and 
often prominent; aperture subtriangular, with three strong plaits on the pillar, 
and, in fully adult shells, some faint liration inside the outer lip; canal short, dis- 
tinct, forming a strong fasciole around a narrow, deep umbilicus, over which the 
inner lip is partly reflected; body with a wash of callus; throat whitish. Height 
of shell, 35; of last whorl, 25 ; of aperture, 18 ; width of shell exclusive of the 
spines, 20 mm. 
U.S. S. “ Albatross,” station 3368, in 66 fathoms, rocky bottom, near Cocos 
Island, Gulf of Panama, temperature 58°.4 F. U.S. N. Mus. 122,996. 
This is the most thorny species yet described. 
Cancellaria (Merica) io Dat. 
Plate 1, figure 2. 
Cancellaria io Dall, Proc. U. S. Nat. Mus., 1896, 18, p. 14. 
Shell fusiform, solid, whitish or pink, with a more or less olivaceous epidermis, 
and about six whorls; spire pointed, whorls rounded, somewhat constricted in 
front of the suture, which is appressed ; sculpture of numerous flattened spiral 
threads, with about equal interspaces, uniform over the whole surface, but with 
