MOLLUSCA. 
9 1 
*v X 
TROCHONEMA HUMIFUSA. 
Plate 2, fig. 14. 
Depresso-turbinata, unciam lata, spira brcvi, anfractibus 5, quad- 
ratis, rugoso-costatis, insuper planatis obliquis, deiude verticalibua 
tricostatis ; subtus—? Sutura planulata. Costa superior maxima, 
remotior ; secunda tertiaque approximate minores, in spira due solum 
vis®. Line® incrementi rugos®, valde obliquse (?) 
A fine shell, the largest of the Gasteropods yet found in these 
regions, except the Bellerophon. It is about an inch in dia¬ 
meter, and rather less in height, the spire being low-turreted 
and the whorls rising step-like from each other. They are 
squarish in outline—the suture somewhat flattened; the upper 
part of each whorl sloping, flat, or nearly so, the sides verti¬ 
cal. At the outer angle the chief of the three ribs is thicker 
and more remote than the lower two, and all are somewhat 
rugose, crossed by irregular lines of growth, so that the shell 
has an antiquated appearance. 
Locality. —Kalajowar, 15,700 feet. (No. 1766.) 
CYCLONEMA RAMA. 
Plate 2, fig. 15. 
C. parva vix tres partes unci® longa, spirata, anfractibus 4-5 
rotundis nec angulatis, concentrice sulcatis. Costul® planat®, insuper 
majores. Line® incrementi obscur®, rectse. 
Pleight about ftlis of an inch, diameter ^ an inch. Whorls 
five or six (our specimen shows only the three lower ones), 
rather tumid, regular, rounded, with no flattening at the 
suture or base, deeply grooved concentrically throughout—the 
grooves rather irregular, broader and coarser on the upper 
half, finer and closer below. The ribs are flat, especially in 
the upper part of the whorl, and crossed by inconspicuous lines 
of growth and a few strong ones which are direct across the 
whorl. Mouth rounded (so far as can be seen—the inner 
margin is concealed by stone). 
The genus Cyclonema was formed by James Hall to include 
those species of so-called Turbo in the Silurian rocks which 
