18 CRETACEOUS GASTROPODA 
A. Adams, but most probably any other would offer equal difficulties, and, at 
present, there seem to be no other possible means of distinction than some artificial 
one, as proposed by Adams and others. 
Fossil forms of Azra are first known, with full certainty, from the Lias (cer- 
tainly middle, if not lower), and they continue numerously represented through all 
subsequent formations, but unfortunately are very rarely met with in good preser- 
vation. The cretaceous deposits are extremely rich in species belonging to this 
family. A nearly complete list of these species will be found in Pictet’s “ Paleontologie 
Suisse 3me. Ser.’ As to geographical distribution, the largest number is known from 
BHurope, especially from the southern part. The American deposits are comparatively 
very poor in species of the Azra, equally as in those of the Vozurrpm ‘The 
fact is in accordance with the representation of these families at the present time. 
The South Indian cretaceous deposits have yielded us a tolerably good number, 
represented by 15 species, which will be found described under five genera; Pug- 
nellus contortus, Sow.; P. granuliferus, Stol.; P. wicatus, Forb.: Aporrhais 
Arrialoorensis, Stol.; Ap. securifera, Forb.: Alaria Parkinsoni, Mant.; Al. 
papilionacea, Goldf.; Al. glandina, Stol.; Al. acicularis, Stol.; Al. tegulata, Stol.: 
Rostellaria? palliata, Forb.; Pterodonta terebralis, Stol.; Pt. bulimoides, Stol.; 
Pt. nobilis, Stol., and Pt. Ootatoorensis, Stol. 
We commence the descriptions of the PRosoprancuta with the family Azaza 
not because they are the most highly organized of this order, but rather on account 
of the difficulty of bringing them into the general scheme, if we began with any 
other family. Our only object here, as already stated, is to shew the relations of the 
different families, genera and species, as composing a local fauna. It is true, that 
maturity reached at a later period and division of different functions on separate 
organs are generally signs of relatively higher organization; the locomotive organs 
are also higher developed than in most other families of Gastropoda. The eyes of the 
Axara are nearly quite as perfect as those of Cephalopodes and Fishes, and the 
separation. of tentacles and eye-peduncles, in a large number of species, could be 
looked at equally asa sign of higher organization, for this division is principally 
developed in the PULMONATA. 
I.* PUGNELLUS, Conrad. 1860. 
Pug. testa ovata, ultimo anfractu plus minusve involuta, crassa, strombiformi ; 
apertura angustata, interne laevigata, marginibus continuis ; labio callosissimo, postice 
accunulato atque sepius spiram tegente ; labro ad marginem crasso, posterius lobuto : 
lobo plus minusve unciforme prolongato ; canali anteriort incurvo. 
The genus Pwgnellus was first proposed by Conrad (Journ. Acad. Nat. Se. 
Phil. IV, p. 284) for four species, P. densatus, Con. from Mississippi, P. tumidus, 
Gabb, from Chili (subsequently described in Proc. Acad. Phil. for 1860, p. 197, PL. 8, 
Fes. 13 and 14), and the South Indian Strombus uncatus and contortus of Forbes. 
Gabb has recently described two characteristic species from California (Pal. of Calif. 
* Genera are numbered continuously in each order; the species in each genus. 
