OF SOUTHERN INDIA. 141 



5. Venerupis, Lamarck, 1818. Shell sub-quadrangular, more or less 

 laterally compressed, posteriorly often somewhat dilatated and gaping; surface 

 radiately ribbed, and at least towards the posterior end laminar ; hinge with 

 three usually distinct sub-equal teeth in each valye, the middle teeth generally 

 are the strongest and furrow^ed; the anterior tooth of the right valye usually is 

 the smallest, but it very rarely becomes obsolete. Lamarck's Donax irus, Linn., 

 is the type of the genus. 



The hinge-teeth of Venerupis are very distinct from those of Eupellaria as 

 restricted; they are sub-equal, close together and diverging, exactly similar to 

 those of Tapes, This form of the hinge-teeth is observable even in those species 

 which are a little ventricose and resemble Eupellaria in form. For this reason the 

 genus has been classed by H. and A. Adams in the tapi:sin^, but the general charac- 

 ter and ornamentation of the shell with the overlapping margins of the mantle 

 anteriorly, as distinctly indicated in some species, further, the rounded form of 

 the small foot and the habitat of the shells, suflaciently indicate their close 

 relation to Fetricola. 



List op cretaceous species. 



Witli tKe exception of a single imperfect specimen, I am not acquainted with any species of 

 FbtricoliDjE from the cretaceous rocks of Southern India^ but a few have been described from other 

 countries. Pictet and Campiche (Pal. Suisse, 4^® ser., p. 163_, &c.^) quote the following : — 



\-4^.—-Petr. neocomiensisj Buv., Pet. Rliodani, P. and R., and Pet. Meriani, P. and C. (both 

 probably belonging to Clioristodon) , Escheri, P. and C. 



Peir. nuciformis and canaliculata of Sowerby are justly excluded from this family altogether; 

 the former is a Corbis, or some allied genus^ and the latter a Cardium. 



5-7. — Venerupis neocomiensis, Buv., Y. Landeroniana, P. and C.^ and V. Saxoneti, P. and C. 

 The two former are known only from cast specimens ; the first may be a Rupellaria ; and the last^ 

 of which Pictet and Campiche only give a short characteristic^ may also belong to the same genus. 



I do not know of any other species having been described since Pictet and Campiche^s 

 publication, 1865. 



8. — Chor'utodon ? A single specimen occurred in the white limestone of Ninnyoor. It 

 has the general form of Clionstodon^ and traces of shell certainly indicate by their earthy and soft 

 structure a species of this genus. The shape is quadrangularly ovate and very tumid ; the surface 

 appears to have been finely striated concentrically; and a deep ascending sinus is indicated^ though 

 not distinctly; vide pi. xvii^ fig. 3. 



XIV. Family— VBNEEII)^. 



The organisation of the animals belonging to the present family must be 

 regarded as characteristic of all the VENBRAGBA, As a rule, the animals have 

 an elongated or roundish oval shape, are moderately thick, have a thin mantle with 

 thick, sometimes crenated edges, united only for a very short distance below the 

 siphons. The gills are large, sub-angular, two on each side ; the palpi generally 

 small. The foot is stout, sometimes thick, sub-quadrangular, but usually prolonged, 

 pointed at the end, and below sometimes furnished with a byssal groove, the byssus 

 being, however, developed only in some of the compressed forms, like Tapes and 



2 M 



