CLASS GASTROPODA 
33 
Periphery of the last whorl marked by a slender cord. Base moderately pro¬ 
longed, ornamented by six spiral cords, of which the two immediately 
anterior to the periphery and the two at the base of the columella are 
decidedly stronger than the rest. Aperture rather large, channeled ante¬ 
riorly; posterior angle stout, twisted, somewhat revolute, and reflected; 
parietal wall glazed with a moderately thick callus. Length, 12.1; diameter, 
4 mm. (Bartsch.) 
Type in United States National Museum, No. 194413. Type locality, 
Deadman Island, San Pedro. 
Range. San Pedro, California. Pleistocene, Santa Barbara, California. 
Bittium munitum Carpenter, 1864 
Report, British Association for the Advancement of Science, 628:1863, 660:1864. 
Proceedings of the United States National Museum , 40; PI. 53, figs. 1, 2. 
C. testa, C. pitrpiireae simili, sed angustiore, marginibus spirae fere 
rectis; costis spiralibus magis expressis, testa adulta minus nodulosis; 
basi aequaliter lirulata. Long., 34; long, spin, 24; lat., 11 poll. (Car¬ 
penter.) 
Shell elongate-conic, yellowish white. Nuclear whorls a little more than 
one (with the sculpture abraded in all our specimens). Post-nuclear 
whorls strongly shouldered at the summit, marked by three, strong, equal 
and equally spaced, spiral keels, which are a little wider than the spaces 
that separate them. In addition to the spiral keels, the whorls are marked 
by somewhat retractive axial ribs, of which 18 occur upon the second, 20 
upon the third, 24 upon the fourth and fifth, and 28 upon the penultimate. 
The intersections of the axial ribs and spiral keels form strong tubercles, 
while the spaces between them are well-impressed, rounded pits. Sutures 
subchanneled. Periphery of the last whorl marked by a strong channel, 
across which the feeble continuations of the axial ribs extend. Base mod¬ 
erately long, marked by six, strong, spiral cords which grow successively 
weaker from the periphery to the umbilical area. In addition to the above 
sculpture, the entire surface of the spire and base is crossed by numerous 
fine lines of growth and exceedingly fine spiral striations. Aperture sub¬ 
quadrate, channeled anteriorly; posterior angle obtuse; outer lip rendered 
sinuous by the external sculpture; columella short, stout, somewhat twisted, 
and reflected; parietal wall glazed with a thin callus. Length, 7.8; diam¬ 
eter, 3 mm. (Bartsch.) 
Type in United States National Museum, No. 15501. Type locality, 
Neah Bay, Washington. 
Range. Sitka Sound to Straits of Juan de Fuca. 
Described as Cerithiopsis munita. 
[635 ] 
