OF SOUTHERN INDIA. 379 
with any of the animals and only very few shells of the Szomarizpm, and as the 
study of the fossil forms is not directly opposed to the usually accepted sub-divi- 
sions, I shall quote the genera from H. and A. Adams’ and Gray’s previous publi- 
cations. 
1. Stomatia, Helbling, 1778 (H. and A. Adams, Gen. I, p. 436). Shell 
oblong, suborbicular, with a short prominent spire, whorls plicated at the suture, 
carinated or tubercular ; aperture laterally and anteriorly very much produced. 
2. Stomatella, Lamarck, 1809 (ibid. p. 485) has a similar shell, but the 
aperture is laterally less produced, the spire usually higher, the whorls spirally 
ribbed or striated, and the internal pearly layer much thinner than in Stomatia. 
3. icrotis, Adams, 1850 (ibid. p. 487), has two tuberculated ridges above near 
the periphery of the last whorl, the inner lip somewhat twisted. The animal has 
a deep fissure in front of the foot. The shell, say H. and A. Adams, resembles a 
little Haliotis without the perforations. 
_ 4. Gena, Gray, 1842 (ibid. p. 487). Shell sub-spiral, oblong, ear-shaped, 
spire very short or indistinct. 
5. Miphonia, Adams, 1860 (Ann. mag. nat. hist., VI, p. 386). Shell like 
Stomatella, but very thin, columellar lip internally thickened and gradually passing 
into the outer one. 
6. Broderipia, Gray, 1847 (H. and A. Adams, Gen. I, p. 438). Shell 
cup-shaped, like a Helcion, smooth, or more usually covered with very fine spiral 
and radiating striz, internally distinctly pearly. 
Fossil species of the Svomarup# occur already in paleozoic formations, and 
continue in small numbers to be found through all the mesozoic and tertiary 
deposits. The recent species are chiefly inhabitants of the eastern seas; they are 
found mostly on coral reefs at moderate depth, and some of them at low water under 
stones. 
There have been four cretaceous species described under the name of Stomatia ; the first by 
d@Orbigny (Pal. frang. terr. crét. II, p. 237, pl. 188, figs. 4-7) as S¢. aspera, which, I rather think, 
is a Sigaretus ; Stomatia gaultina, Pictet and Roux (Moll. Grés verts, p. 245, pl. 24, fig. 8) has’ 
the general form of a Stomatella, but it is as yet only known from a cast; Stomatia ornatissima, 
Coquand (Ktage Aptien de l’Espagne, 1865, p. 74, pl. 5, figs. 4-5) is more likely an Astralium ; 
Stomatia bicarinata, Guéranger (Album pal. de Ja Sarthe, 1867, pl. 10, fig. 8. Sigaretus ? id. olim.) 
is to all appearance a true Stomatia. I have nothing to add from South India, 
V. Sub-order,—Fissobranchiata. 
The animals possess, as far as known, a thick fleshy foot, usually having on 
the upper part a fringe consisting of numerous, short and uniform cilia, rarely 
are there two or three pairs of long lateral appendages present ; the head is distinct, 
with thicker or thinner, but always elongated, tentacles, having the eyes on more 
or less thickened peduncles on their outer side and a complete, or divided and 
denticulated veil between each other; rostrum usually produced; the teeth resemble 
those of the ScUTIBRANCHIATA in general (Rurprpoetossa of Troschel, Lovén 
