FOSSIL. CHRHATOPODA. 
aN 
nN 
oO 
The largest example is part of a widely umbilicated specimen 
with coarse ribs, and attained a large size. Its length along the 
median line of the periphery is about 170 mm.; at the anterior 
end its height is 44 mm., and its width 45 mm., but one side of 
specimen is very much worn. The radius of curvature of its inner 
edge is about 58 mm. (or rather more than 24 inches). The 
primary ribs (14 in number) are forwardly inclined; each divides 
usually into two, but sometimes into three ribs, which pass unin- 
terruptedly over the peripheral area. It seems to have been as 
coarsely ornamented as the Per. ¢orguatus figured by Waagen! 
from that part of the Katrol Group which he refers to the Kimer- 
idge Group. The ribs are coarser, and the whorl is more inflated 
and relatively wider than in the types of Sowerby’s Asm. biplex* 
from the Kimeridge clay, although not so wide as the type of his 
Amm. rotundus® from the same horizon. 
One of the other fragments appears to be the posterior part of a 
body-chamber. It is only about 66 mm. long, semi-elliptical in 
transverse section, with the sides a little flattened. In this length 
there are eleven primary and twenty-two secondary ribs. The 
primary ribs are nearly straight, radial, and at the outer two-fifths 
of the lateral area divide usually into two, rarely into three branches, 
which pass straight and uninterruptedly over the periphery. Occa- 
sionally a primary rib passes over the whorl without bifurcating. 
The height of the whorl at the centre of the fragment is 28 mm., 
and its width is about the same. 
The collection, although fragmentary, shows that the rocks from 
which these fossils were derived are of the Upper Jurassic age, 
almost all the Ammonites being comparable with Indian Jurassic 
species. Many of the specimens, although considerably worn, are 
not at all crushed, so that if specimens could be found in the rock 
2 situ they would in all probability be in a good state of preserva- 
tion and show that the Cephalopoda are not only for the most part 
comparable, but identical, with Indian Jurassic forms. 
# Pal, Indica, ser. 1x., Jurassic Fauna of Kachh, vol: i, p. 191, Pl. LIV. 
2s yiin-«Gon.. vol. 111.,4p.0163,,Pl.. CCX CII, figs. 14:2, 1821. [ Brit. Mus. Coll. 
No. 43898. | 
Said eVol,iil.,.p. 169, Rl CCXCIII., fie. 3, 1821) [Brt.Mus; Coll.: No. 
43899. J 
