OF SOUTHERN INDIA. 63 
1. ONISCIA COSTELLATA, Stoliczka. Pl. V, Fig. 9. 
On. testa ovali, antice caudata, postice apice acuta; anfractibus 6-7, scalari- 
Sormibus, ad suturam posteriorem valde constrictis, transversaliter costulatis : costulis 
acutis, prope rectis, circiter 18 in wno circuitu; apertura angustissima, lineari, labro 
ad peripheriam valde incrassato, interne denticulato, labio calloso, postice acumina- 
to, elevato, dense crenulato ; canali moderato, recurvo. 
Width of the last whorl : height (consd.as 1:00) ... cn os 0°68 
Height of aperture : total height of shell (consd.as1:00) .. 4. 0°63 
Shell elongated, considerably tapering towards each end, consisting of six or 
seven volutions, the last of which by far exceeds the previous in size, so as to form 
about three-fifths of the total height of the shell. On the upper or posterior suture 
the whorls are much constricted, each ornamented with about 18 nearly straight 
and sharp transverse ribs. Of spiral strize there are scarcely any traces perceptible, 
and they must have been very fine. The aperture is very narrow and oblique, 
forming a slight curve. The outer lip is at its margin, and especially at the outer 
edge, very thick, little expanded and reflected, internally in its entire length denti- 
culated; the inner is callose, especially posteriorly near the suture, where it is consi- 
derably elevated, covering the greater part of the front or ventral side of the last 
whorl; it is all over finely crenulated and, in the middle of the space of the aperture, 
slightly insinuated. The canal is proportionally long, thin, recurved and on the 
termination emarginate. 
The somewhat inflated form in the middle of the shell, the sharp transversal 
ribs, the prolonged and recurved canal, the narrowness of the aperture and the want 
of the insinuation on the outer lip distinguish this species without difficulty from 
Cythara cretacea, nu. sp., even when the inner lip or its granulation is not well 
preserved. 
Locality.—South of Arrialoor in Trichinopoly District, where the single figured 
specimen was found. 
Formation.—Arrialoor group. 
VI. Fanily,— PLEHUROTOMIDZ. 
(TurRiripz, Adams, non Gray.) 
The common character of the different genera usually admitted into this family, 
reduces itself to fusiform shells with a posterior notch on the outer lip. 
The animals are all very similar; they have an oval and simple foot, enclosed 
mantle, approached subulate tentacles, with the eyes on the outer side near the 
base or the middle; subulate, elongated teeth ete., all characters in which they 
resemble the Coyzpz. Deshayes was among the first who drew attention to the 
relations of Plewrotomaand Conus. The newer observations of the animals by Quoy, 
