3852 : APPENDIX. 
above, with a minute submarginal apex ; inner lip large, flattened 
or slightly convex, the margin smooth or crenulate; outer lip 
usually a little thickened and sometimes crenulate within, and 
more or less continuous with the inner lip; aperture compara- 
tively small ; surface smooth or radiately ribbed ; usually polished. 
Differs from Dostia in its more nearly perfect bilateral symmetry 
and minute apex; from Velates in its marginal apex. 4 sp. 
Cretaceous and Laramie; U. 8. 
CycLostrEMA, Marryat [p. 299]. 
THARSIS, Jeffreys, 1883. (Htym.—One of the many synonyms 
of Cyprus.) Shell globular, solid and glossy; peristome circular 
and continuous, but attached to the pillar on that side; base 
closed by a pad or thick testaceous layer in the adult, perfor- 
ated in the young; operculum chitinous or horny, and multispiral. 
This genus differs from Cyclostrema in the peristome being, 
although continuous, not free or detached from the rest of the 
shell, and in the umbilicus being closed instead of open in the 
adult. Type, 7. Romettensis, Sezuenza. Mediterranean. 
GANESA, Jeffreys, 1883. (Htym.—The Hindoo god of science.) 
Shell shaped like a Natica, thin ; peristome continuous, free and 
separate in the young, but united to the periphery in the adult; 
spire having an oblique axis; base perforated, not umbilicate ; 
operculum horny, multispiral. Differs from Tharsis in the ob- 
liquity of the spire and the perforation of the base at every 
stage of growth. 2sp. Hurope. G. pruinosa, Jeffreys. 
Fissurellide [p. 326 ]. 
? Dirinus, M’Coy, 1844. 
Disir.—D., Bucklandi, M’Coy. Carboniferous; Ireland. 
Patelliform ; apex perforated by two oval foramina, symmet- 
rically placed one on the right side, the other on the left. 
A very problematical fossil. 
Cynicuna, Lovén [p. 359]. 
CRYPTAXIS, Jeffreys, 1883. Shell small, white, glossy,sometimes 
with fine revolving striw; spire deeply sunken, and for the most 
part concealed in a small cavity in the centre of the crown, but 
showing the apex and sometimes one or two whorls at the bottom 
of the cavity. 4sp. Deep-sea; Europe.  C. crebripunctatus, 
Jeffreys. Intermediate between Cylichna and Utriculus. 
Ruoporg, Kolliker [p. 391]. 
This is not a mollusk, but a peculiarly aberrant Turbellarian. 
—Science, i, 433. 
