OF SOUTHERN INDIA. AL 
With very few exceptions nearly all the species of P/erodonta were found in the 
deposits of Southern Europe, and of the two found in Algeria, one is identical with a 
French species. I am not acquainted with a single species from the Alpine Gosau- 
deposits, and cannot offer the slightest opinion as to the P?. toucasiana, which D’Orbigny 
quotes as occurring also in the Gosau (Prodrome II. Varigera id. p. 221). Perfectly 
inexplicable remains to me also the ground, upon which D’Orbigny transferred (ibid. 
p- 221), the Zornatella abbreviata, Philippi, to his Varigera, in spite of the Gosau 
shell being distinctly canaliculated in front, and having at least one distinct fold on 
the columella. Pictet (Mat. Pal. Suisse. 8me ser. p. 359) believed it an Acteonella, 
according to Zekeli, but I have already shown in my ‘ Reyision of the Gosau Gastro- 
poda’ (Sitzungsb. k. Akad. Wien, LII, p. 42), that the species is an I/eria, a genus 
of the Pyraurprrtrpm. Inthe cretaceous deposits of Northern Europe only very few 
sporadic species have been noticed. Drescher described lately one (Zeitsch. deutsch. 
geol. Gesellsch, vol. xv. p. 839, Pl. IX. Fig. 12), which he identifies with P?. inflata, 
D’Orbigny, although I do not think this identification very successful. The con- 
vexity of the whorls is rather different in the two species. The impressions of the 
internal folds on the upper whorls in Drescher’s specimens reach posteriorly nearly 
to the suture, while they scarcely ever appear traceable on the upper whorls of the 
original Péer. inflata; the inner fold or varix being in this species much shorter. 
As regards this point, Drescher’s specimen shows more close relation to our 
Pterodonta Ootatoorensis. At the same time there is no necessity to be in great 
haste to find a new name for the German specimen, as it is merely an «complete 
cast. } 
I would take this opportunity of calling attention to two species, which occur 
in the hippuritic limestone near Kutschlin in Bohemia, namely, Plerocera gigantea, 
Geinitz, and Pé. gracilis, Reuss (Verst. Boehm. Kreidef. 1845, p. 48, Pl. XI., Figs. 
14, 15 and 21). Both have the general form of true Pferodonte, and the shell appears 
to have been smooth and thick. The latter species has been already supposed by 
D’Orbigny to be a Pterodonta (Prod. IL., p. 191), but nothing positive can be ascer- 
tained, until the specimens have been carefully re-examined. We may have then 
within the Mediterranean circle of the cretaceous deposits nearly thirty species of 
Pterodonte, but I need scarcely repeat, that most of them are known from deficient 
casts only, and it is very possible, that the discovery of better materials may reduce 
this number to one-half or two-thirds. I am not aware of any species having been 
described from the American cretaceous deposits; or from Australia. 
The South Indian cretaceous rocks have yielded four species, three of the typical 
Pterodonta, and one belonging to that group of fusiform shells. Two of the fossil 
species are characteristic for the lowest beds, the Ootatoor group, namely, Pt. Oota- 
toorensis and Pt. terebralis; the Pt. nobilis occurs in the Trichinopoly, and the 
bulimoides in the Arrialoor beds, 
