APPENDIX. : 353 
Wor. 1 
PELECYPODA. 
Cyprinide [p. 187]. 
Rovuparrera, Munier-Chalmas. 
Syn.—Trigonocardia, Zittel. 
Distr.—Cretaceous; N. Africa, India. R&. Drui, Mun.-Chal. 
(exv, 49-51). 
Shell trigonal or trapezoidal, thick, convex ; beaks prominent, 
incurved, anterior, with a deep lunule under them; posteriorly a 
sharp keel, behind which the surface is smooth, the rest of the 
shell being folded; hinge-margin thick; the right valve with 
three cardinal teeth, the posterior one separated from the central 
by a deep pit, and divided, the anterior tooth horizontal, there 
is a strong posterior lateral tooth; in the left valve the posterior 
cardinal is small, the middle one very large, the anterior divided, 
its branches diverging, posterior lateral tooth strong ; anterior 
muscular impression upon a raised base; ligament external. 
PrycHopEsMA |p. 269]. 
Fourth line of description, for “ Planorbis,” read “ Pec- 
tunculus.” 
