CLASS GASTROPODA 
249 
Type in United States National Museum, No. 32259. Type locality, 
Gulf of California. 
Range. San Diego, California, to Gulf of California. 
Trifora carpenteri Bartsch, 1903 
Plate 71, fig. 16 
Proceedings of the United States National Museum, 33:252; PI. 16, fig. 16. 
Shell elongate-conic, almost cylindric, bleached white. (Early whorls 
decollated.) Later turns ornamented by three spiral ridges, of which the 
posterior one is a little more strongly developed than the other two and 
forms the summit of the whorls. The other two spiral ridges are equal 
and equally spaced. In addition to the spiral ridges, the whorls are marked 
by axial ribs, about as strong as the spiral ridges, the intersection of the 
ribs and ridges forming strong tubercles, while the spaces inclosed between 
them appear as deeply impressed square pits. There appear to be about 
twenty-two tubercles upon all the whorls. The sutures appear as broad, 
deep channels which are crossed by the extensions of the ribs. On the last 
three turns the posterior edge of the peripheral keel is apparent in the 
suture. In addition to the above sculpture, the entire surface of the spire 
is marked with microscopic lines of growth and equally fine striations. 
Periphery of the last turn marked by a strong spiral keel. Base marked 
by two strong rounded keels, of which the posterior one is separated about 
as far from the peripheral keel as that is separated from the supra- 
peripheral one. The anterior keel of the base is situated on the columella 
and is separated by a little wider and deeper channel from the posterior 
keel than that is from its posterior neighbor; anteriorly it is limited by a 
feebly impressed groove. The channels of the base are crossed by weak 
continuations of the axial riblets. Aperture ovate, strongly channeled 
anteriorly and moderately so posteriorly; columella short, stout, and 
twisted; covered by a strong callus which also extends over the parietal 
wall. Length, 7.2; diameter, 2.2 mm. (Bartsch.) 
Type in United States National Museum, No. 15583. Type locality, 
Neah Bay, Washington. 
Range. Known only from type locality. 
Trifora callipyrga Bartsch, 1907 
Plate 71, fig. 4 
Proceedings of the United States Natioml Museum, 33:251; PI. 16, fig. 4. 
Shell elongate, conic, subturreted, uniformly light brown. (Early 
whorls decollated.) The remaining seven are separated by strongly im¬ 
pressed sutures, and are ornamented with three spiral tuberculate keels on 
[ 547 ] 
