118 
liecords of the Geological Survey of India. 
[voL. XI. 
For the moment, it will be afs well to attend to Trigonia wewin'cosa and Tr. vcmi 
alone. Both these shells were found elsewhere in the district near Port Elizabeth 
in beds supposed to be at a lower horizon, but they are there comparatively rare 
and isolated,1 whereas in the uppermost bed on Sundays river they are so ex¬ 
tremely abundant as to be characteristic. The next bed below the IVigonia zone i.s 
very important, because it is the only one containing llamites Africanm and the 
lowest with Grassatella complicata, both forms with distinct cretaceous affinities,® 
but another species peculiar to the bed is Belemnites Africanus, a near ally of B. 
Grantianus ( B. Kimhotensis of Waagen) one of the most typical fossils of the 
Katrol group of Cutch, and ranging into the bottom beds of the Umia group. 
At the same time amongst the remaining fossils in the Modiola and llamites Zone 
on the Sundays river one is identified with Trigonia Goldfus f a lower oolite 
(middle Jurassic) fossil, and Modiola Baini is also related to a great oolite species, 
but the Modiola and Mytili are by no means characteristic forms, and cretaceous 
or even later allies might easily be indicated. In another stratum on the Upper 
Sundays river,* together with Modiola Baini and apparently on the same 
horizon, Anvmonites swhanceps is found, and this form is but dubiously separable 
from A. anoeps of the lower Chari beds in Cutch and Callovian of Europe. It is 
thus evident that there is too largo a representation of middle Jurassic fossils to 
Justify the reference of the llamites bed to neocomian, but still there can be no 
quo.stion of its occui^ying a very high Jurassic horizon, and the zone of Trigonia 
ventricosa and Tr. vau is even higher. 
Trigonia Ilerzogi, in the section on Lower Sundays river, was only found at a 
considerably lower horizon than Tr. ventricosa, but on Upper Sundays rivet’ it was 
found in a bed overlying the Modiola zone and apparently, accordino- to 
Mr. Stow, as high in the series as the Tr. ventrkosa band. 
Gervilla dentata of the Hamite bed on Sundays river is apparently identical 
with a species found in the Umia gi-oup. If not identical, the forms are very 
closely allied. 
A comparison of Mr. Lydekkor’s remarks’ on the fragment of a Plesiosaurus 
mandible from the Umia beds, will show that Dr. Feistmantel overrates the 
importance of the occurrence. Plesiosaurus ranges from Has to cretaceous, and 
the occurrence of more numerous species in the former is duo to the preservation 
of many specimens at one favoured locality. As the mandibles of the upper 
oolitic and cretaceous forms are not known, the fragment from the Umia beds 
was at first compared to a liassie species, but it subsequently j)roved to be distinct. 
The specimens attributed to Goniomya V.-scripta I am unable to find in the 
Survey collections. It is possible that there may be some mistake about the 
identification, and I have reasons for bebeving that the fossils at first supposed 
' 1. c., p. 502. 
= See Tate: Q. J. G. S., 1867, vol. XXIII, pp. 150, 160, 165. 
3 This species, however, in South Africa appears to pass up into beds of prohahly cretaceous 
age. Stow : 1. c.. pp. 513, 514, 
“ Stow: 1. c., p. 503. 
“ Ilec. G. S. I., vol. IX., p. 154,- vol. X., p. 41. 
