CLASS GASTROPODA 
229 
narrow peripheral keels, with a narrow interspace inclosing the anal sulcus 
and fasciole; on the outer side of each keel is a moderate constriction of 
the whorl; the suture is laid just below the anterior keel; there are also 
very minute spiral threads over the whole surface which do not reticulate 
the axial sculpture; the latter is composed of retractively arcuate, uniform 
minute, close-set threads extending over the flatfish upper surface of the 
whorls, and the roundly convex base; axis perforate, the umbilicus small, 
the aperture rounded except the rather straight, somewhat reflected, short 
pillar lip; operculum multispiral, whitish, subtransparent. Height, 2.5; 
diameter, 3 mm. (Dali.) 
Type in United States National Museum, No. 206509. Type locality, 
U.S. Fish Commission Station 3340, southeast of Chirikoff Island, Alaska, 
in 695 fathoms. 
Range. Known only from type locality. 
Genus SCHISMOPE Jeffreys, 1856 
Schismope is a Scissurella in which the anal slit becomes closed in the 
adult, and transformed into an oblong perforation like one of the holes 
of a Haliotis . It bears much the same relation to Scissurella that Trocho- 
toma does to Pleurotomaria. The species inhabits deep water; there are a 
number of fossil forms described. (Tryon and Pilsbry, Manual of Con- 
chology.) 
Type. Schisomope cingulata Costa. 
Distribution. Mediterranean, New Caledonia, West Indies, Aus¬ 
tralia, Tasmania, Cape Verde Islands, Gulf of California, and California. 
Schismope rimuloides Carpenter, 1865 
Proceedings , Zoological Society of London, 271. 
S. t. rapide augente, albida, tenuissima; apice celato; anfr. iii., radiatim 
liratis, liris subdistantibus, acutis, obliquis; umbilico magno; labro declivi, 
haud fisso, sed apertura postica, ut in Rimula formata, subquadrata, elon- 
gata; liris transversis gradus testae increscentis definientibus; peritremate 
continuo, oblique. (Carpenter.) 
Shell rapidly enlarging, whitish, very thin; apex concealed; whorls 
three, radiately lirate, the lirae subdistant, acute, oblique; umbilicus large; 
lip sloping, scarcely fissured, but with an aperture formed posteriorly as in 
Rimula, subquadrate, elongate; peristome continuous, oblique. Alt., .023; 
diameter, .03 in. (Tryon and Pilsbry, Manual of Conchology.) 
Type in Liverpool Collection. Type locality, Mazatlan, off Spondylus. 
Range. South Coronado Islands to Mazatlan, Mexico. 
[ 831 ] 
