MOLLUSC A. 
19 
at tlie keel, which is a narrow and prominent band, placed 
but little below the exposed portion of the whorl: the part 
above the band is slightly convex; the suture not at all ap- 
pressed; the part below concave to a second prominent keel. 
The short basal portion is not produced (as it is in many 
species) or marked by any spiral ridges. Nor are there any 
on other portions of the whorl. The lines of growth are 
rather obscurely marked out, and their exact direction is not 
ascertained. Mouth ?—Diameter of the base four-tenths of 
an inch. Height of shell about six-tenths. 
Locality. —Ivalajowar, 15,700 feet. (No. 1766.) 
PLEUROTOMARIA TURBINATA. 
Plate 2, Fig. 11. 
P. parvula, brevis, anfractu ultimo subhemispherico insuper pla- 
nulato seu concavo, subtus convexo fere gibbo. Carina superior bi- 
carinata. Superficies lineis concentricis tenuibus,—incrementi re- 
trorsis. Umbilicus perforatus. 
A small neat species, much resembling some carboniferous 
forms. The diameter only a quarter of an inch, the height 
rather less. 
The last whorl only is preserved in our specimen; it is flat, 
or slightly concave above, and highly convex below, almost 
gibbous as it turns inwards toward the open umbilicus. 
The surface is covered with fine concentric lines, not very 
distinct; these occur both above and below the double keel, 
which is concave between its two bounding ridges. 
Locality .—Chorhoti Pass, 16,000 feet. (No. 1754.) 
RAPHISTOMA EMODI. 
Plate 2, fig. 12. 
R. modica, lineas 5 lata, discoidea lenticularis, spira depressa py- 
ramidata, anfractibus 5, insuper fere planis, paullo coneavis, carina 
submarginali filiformi instructis, subtus convexiusculis. Striae incre¬ 
menti regulares filosse, valde retrorsum curvae. 
The shell is discoid-lenticular, 5 lines broad, and only 21- 
lines high, of a low pyramidal shape, with 5 whorls and a 
