320 PLEUROTOMARIID®. 
whorl. At the place where this is deflected there is an elongated, 
kidney-shaped perforation surrounded by somewhat thickened 
margins ; another small perforation is found about the centre of 
the basis, but in the outer lip it is likewise surrounded with a 
raised margin. 
? BRILONELLA, Kayser. 
Distr.—B. serpens, Kayser. Devonian; Germany. 
Last whorl unwound and deflected upwards, so that the mouth 
lays upon the top of the spire; otherwise like Pleurotomaria. 
ODONTOMARIA, Roemer. 
Distr.— O. elephantina, Roemer. Devonian; Hifel. 
Shell not spiral, extended-tubular, somewhat curved; mouth 
with slit terminating an external band. 
TrocHoToma, Lycett. 
Htym.— Trochus, and tome, a notch. 
Syn.—Ditremaria, d’Orb. Rimulus, d’Orb. 
Distr.—Fossil, 10 sp. Lias to Coral Rag; Britain, France, 
ete. T. Humbertina, d’Orb. (1xxxii, 90). 
Shell trochiform, slightly concave beneath; whorls flat, spirally 
striated, rounded at the outer angles; lip with a single per- 
foration near the margin. 
'TEMNOTROPIS, Laube. 
Distr.— T. carinatus, Goldfuss. Trias; St. Cassian. 
Shell ear-shaped, with rapidly enlarging keeled whorls, and a 
very large oval aperture; outer lip sharp with a deep slit, ter- 
minating a slit-band on the keel. 
DirreMARiA, Deslonge. 
Distr.—2 sp. Great Oolite and Coral Rag; France and 
Germany. D. quinquecincta, Ziet. (1xxxii, 91). 
Shell trochiform; in place of the slit of Trochotoma, there 
are two elongated oval holes united by a transverse fissure; the 
base of the sheli presents a large callosity, the umbilicus is deeply 
excavated, and a round tubercle arises from it; the aperture is 
contracted, and the upper angle of each lip bears a more or less 
distinct tooth. 
ScHisMopE, Jeffreys, 1856. 
Etym.—Schisme, a slit, and ope, a hole. 
Syn.—W oodwardia, Fischer, 1861. 
Distr.—4 sp. Mediterranean, Japan. Fossil,1 sp. Miocene; 
Bordeaux. 
Shell like Scissurella, but the spire is laterally compressed, as 
in Stomatia, and is not so trochiform. The slit in the peristome 
