OF SOUTHERN INDIA. 217 
2. TURRITELLA (Torcvta) PONDICHERRIENSIS, Forbes, Pl. XVI, Figs. 18, 19; 
PE XIX, Hig. 8. 
1846. Twrritella pondicherriensis, Forbes, Trans. Geol. Soc., Lond., Vol. VII, p. 123, Pl. XIII, Fig. 4, 
1847, A angulata, D’Orb. Voy. Astrolabe, Atl. Paléont., Pl. III, Fig. 27, (non id. Sowerby, 
D’Orbigny, 1842, and others). 
1850. i Pondicherriensis, in D’Orbigny’s Prod. II, p. 218, including Turr. angulosa, D’Orb.—=T. an- 
gulata in the Voy. of the Astrolabe. 
Turr. testa elongate-conica, crassa; anfractibus ad margines tumescentibus, 
suturis profundis sejunctis, ad medium paulo excavatis atque 5-6—liratis, liris sim- 
plicibus, tenuibus, semper sulca mediana divisis ; superficie striis minutis spiralibus 
atque transversalibus decussantibus ornatis, ultimis paulo insinuatis ; basi ad periphe- 
riam subcarinata, applanata, spiraliter striata ; apertura rotundate angulata. 
Spiral angle 25°- 30°; sutural angle 5°- 6°. 
Approximate height of last whorl : total of shell (considered as 1:00) ... w. 0:20. 
A % of penultimate whorl : height of spire (considered as 1:00) 0°16. 
39 5p 0 » + its width (considered as 1-00) sno) O49) 
The posterior margin of each of the whorls is always strongly thickened, 
forming a broad slightly rounded ridge; the anterior marginal thickening always 
forms a smaller and narrower ridge; occasionally it is nearly obsolete. The middle 
portion of the whorls is excavated, and in regularly grown specimens orna- 
mented with six spiral ridges, being divided in the middle by a somewhat broader 
furrow into sets of three each. The most anterior or lowest ridge is always the 
strongest and sometimes the next above it is united with it, giving it a still greater 
thickness ; in such cases only five spiral keels are present. On the other hand, in 
cases where the anterior sutural ridge is very narrow, there appear to be seven 
instead of six keels present. Young specimens have generally only the posterior 
marginal ridge quite distinct. 
The entire surface of the shell is besides covered with fine spiral strize, which 
are very much interrupted, rough and undulated by the striz of growth. The 
latter are distinctly insinuated somewhat above the middle of the height of each 
whorl, and equally undulating in their course. The aperture is roundish angular; 
the shell is remarkably thick, the section of the whorls internally nearly circular. 
Localities—Near Pondicherry, in bluish, calcareous sandstone, and near 
Arvrialoor, in whitish soft sandstone. 
Formation.—Arrialoor group. I think the extent of the Valudayoor group, 
as being the lowest and about equivalent to the Ootatoor beds, must be accepted 
very cautiously. The larger number of fossils from these Pondicherry beds are 
rather identical with those from the Arrialoor group. 
3H 
