378 CRETACEOUS GASTROPODA 
2. ? DELPHINULA ROTELLOIDES, forbes, sp. Pl. XXVIII, Fig. 18. 
1846. Trochus rotelloides, Forbes, Trans. Geol. Soc., Lond., VII, p. 120, Pl. XIII, Fig. 10. 
1850. Turbo ad. d@Orbigny, Prod. II, p. 224; idem auctorum. 
| 7. testa depressissima, spiraliter striata, anfractibus superioribus planis, ultimo 
compresso, rotundato ; basi umbilicata, spiraliter striata|, Forbes, loc. cit. 
Forbes’ figure, which we reproduce with a slight alteration, gives only a general 
idea of the characters of the species. The original specimen is very imperfect ; 
it may be a Delphinula, though it is not unlike imperfect specimens of Ninella 
or Marmarostoma. . 
In Fig. 10@ Prof. Forbes represents a few stronger spiral strize, which give the 
shell an appearance of a Plewrotomaria, but there is no distinct band traceable 
on the original specimen. The strive of growth are continuous from the suture to 
the middle of the last whorls, on the basis of which they appear to be much thinner. 
Along the posterior margin the whorls are provided with a slight swelling, below 
which there is a narrow flat portion marked with somewhat finer spiral striz, than 
on the rest of the shell. 
Locality—Pondicherry, in light bluish calcareous sandstone. 
Formation.—? Arvialoor group. 
LIV. family, —STOMA TID. 
Gray, Cat. 1857, p. 158; H. and A. Adams, Gen. I, STOMATELLINZ, p. 435. 
Animal depressed, with a largely developed, fleshy foot ; head distinct, rostrum 
thick, produced, tentacles long and thin, eye-peduncles short and thick, two frontal 
lobes between the tentacles; upper part of the foot surrounded by a fringe 
consisting of numerous short, uniform filaments, mantle entire; branchial plume 
single, with two rows of thin strands; teeth similar to other ScUTIBRANCHIATA. 
According to the figure (19, pl. 66 bis, in Zool. Voy. Astrol.) of Quoy and Gaimard 
the central teeth appear to be wanting, the inner lateral are three on each side, 
thick and simply hooked, the outer lateral are numerous and uniform; other 
forms distinctly show a central tooth and a large number of inner lateral which 
are always stronger, than the inner ones. 
Operculum thin, horny, few whorled, occasionally wanting. 
Shell depressed, consisting of few rapidly increasing whorls, spire very short, 
often quite indistinct ; aperture entire, very wide, pearly within. 
According to Gray, the family consists of five genera. HH. and A. Adams also 
place in it Scissurella (Anatomus), which more properly belongs to the Pzzvroroma- 
rips. In his last Catalogue (Mrs. Gray’s figures of Moll., 1859, vol. IV, p. 90) Gray 
distinguishes only two genera, Stomatella and Gena, to which Broderipia certainly 
ought to be added, but this tri-division of the family is probably all that is at 
present required, or rather that can without great difficulty and uncertainty be 
carried out with respect to generic distinction, As I am, however, not acquainted 
