OF SOUTHERN INDIA. 299 
from the South Indian cretaceous rocks will be found noted subsequently ; they 
belong, as already stated, to five genera, namely, Amawropsis, Ampullina, Buspira, 
Gyrodes, and Mammilla. 
Thus the total number of all the known and well characterized cretaceous 
species amounts to more than one hundred. This number, however, does not repre- 
sent the complete fauna of Narroip” during the cretaceous period, and still the 
known recent species scarcely exceed it by more than an additional half. This 
clearly shows how much more numerous the Nazricrp* were in former times, than 
they are at present. Representatives of the family are to be found in the lowest 
fossiliferous deposits, and they attain very great importance as early as the car- 
boniferous period. ‘They are found in the greatest variety in the lower secondary 
deposits, though not much more in the triassic than in the jurassic period. The 
older species chiefly belong to the genera Amauropsis, Ampullina and Luspira, 
usually possessing a regularly conical spire and the columella solid or slightly exca- 
vated; the tertiary species, however, approach much nearer to the living forms, 
mostly belonging to the genus Natica proper. They are widely distributed, though 
certainly more numerously represented in tropical, than in temperate seas. 
Viewing in general the characters of the cretaceous Narrcrpa, it is remarkable 
that there are among them so very few species of real Natica, the species of which 
have a wide wnbilicus and a distinctly twisted columella. Most of the cretaceous 
forms belong on the contrary to Amauropsis, Ampullina or Huspira, and the 
depressed forms to Gyrodes which has the inner lip less thickened. Species of 
Neverita, Manmilla and others are comparatively rare. 
LXIV. AMAUROPSIS, Wérch, 1857: 
1. AMAUROPSIS PANNUCEA, Séoliczka, Pl. XXI, Fig. 10; Pl. XXII, Fig. 1. 
Amaurop. testa ovato-elongata, spira turrita, acuminata; anfractibus circiter 
septenis, convexis postice ad suturam truncatis sew sub-canaliculatis ; ultimo spira 
altiore ; superficie in junioribus speciminibus spiraliter minute striata, in etate adulta 
sub-levigata ; apertura elongate semilunari, obliqua, postice acuta, antice rotundata, 
labro tenui, ad marginem acuto, labio paulo incrassato, arcuato; columella rimata, 
in adultis speciminibus ad basin callositate labii tecta. 
Spiral angle 70°- 75°; sutural angle 6°. 
Height of aperture : total of shell (considered as 1-00) seal OiGas 
An ovate shell, consisting of about seven volutions, the last of which is inflated 
and higher than the spire. The sutures are deep, each of the whorls being 
posteriorly somewhat flattened, or slightly canaliculated. The aperture is oblique, 
semilunar, with a thin outer lip, the inner lip being moderately thickened. Young 
specimens have a distinct fissure at the basis, but in old ones the end of the columella 
is occasionally quite covered by the expansion of the inner lip (Pl. XXI, Fig. 10). 
The surface is spirally minutely striated, though in large specimens the striz often 
become obliterated, or at least much less distinct. : 
