OF SOUTHERN INDIA. . 157 
broader and shorter than the American type. I must remark here that the 
above description has been taken from the single specimen, before it became unfortu- 
nately injured by dropping accidentally into a bottle with acid. It could not be saved. 
until the surface had become rather corroded and polished in place of the tubercles, 
which, therefore, are only indicated in the representation on Pl. XITI, Fig. 6. 
Locality.—Serdamungalum, in hard siliceous sandstone. 
Formation.—Trichinopoly group. 
XV. Funily—TRICHOTROPID. 
Vide Adams’ Gen. I, p. 278; Gray’s Guide, 1857, pp. 43 and 77, VERENADM and Trichotropis ; 
Chenu’s Man. I, p. 278.) 
It will be sufficient to refer here to the above papers, in which the organization 
and the peculiarities of the animals of Trichotropis will be found treated at length. 
Gray places Trichotropis in the family Aporraarmsz (sub-fam. sporrzainz), 
for which scarcely any other reason than the similarity in the dentition can be 
given, although this appears to be by no means constant, as seen by a comparison 
of the teeth of Trich. borealis and bicarinata. Speaking of the Verzvapa/ (=Tricho. 
borealis, 1. cit. p. 48; Verena id. p. 44-not Verena, Adams; Tropiphora id. p. 77), 
Gray says, “this family is the Buccinoid representative in this group,” and compar- 
ing the animal with that of Purpura, or for instance of Cominella of the Buccryipz, 
the resemblance. will be found far greater than at first sight it would appear. The 
operculum in form and position in the aperture is unquestionably more like the 
Bouccryrpz than Aporrhais or Struthiolaria. The shell appears in reality to forma 
transition between Rapana of the Purpvrrp# and Trigonostoma of the CancrLtarupaZ 
and the place which has been assigned to the Trrcnorrorips by H. and A. Adams 
next to the last named family appears certainly the most probable to be correct. 
The tropical forms of Trichotropis, like 7. cancellata, in their ornamentation resem- 
ble Cancellaria still more. Species of Zrigonostoma would in fact be inseparable 
from Trichotropis, if they had no columellar plaits, so far as the form of shell is 
concerned, but its thickness may be said without exception to be greater in the former 
than in the latter genus, and if this could be considered of greater value than the 
want of columellar plaits, we cannot help confessing that the two species which we 
note under Trichotropis would have to be classed in the Cancerzarix. It must, 
however, be remembered that the single lamellee, which compose the shell of rich. 
Konincki,—the only species we can consult, the other one being imperfect and 
doubtful,—are quite as thin as in living species of Trichotropis, and that the thickness 
of the total shell is only produced by their overlapping each other. 
Alora, Adams, 1861 (Proc. Zool. Soc. Lond. p. 272) has been proposed for an 
American species (4. Gouldii) with a very small umbilicus, and a produced, 
anteriorly non-canaliculated aperture. This character evidently recalls very much the 
form of many fossil species of Purpurina. It would seem that Separatista, Gray, 
2B 
