22 
CRETACEOUS BRACIIIOPOUA 
0. Terebhatula subrotunda, Sowerhy, PI. VI, Eigs. 1 — 23. 
1813. T. suhrotunda, subundata et scmir/lobusa, Soworby, Min. Conch., i, pp. 45, 47, 48, pi. xv, figs. 1, 7, 9. 
1852. T. semiglobosa, apud Davidson, Brit. Grot. Brach., p. 04, pi. viii, figs. 6 — 18 (cum. syn.). 
1808. T. subrotunda, apud Scblccubacli, Sitz. Akad., Wien, Math. Nat. Klasse, vol. Ivii, pt. i, p. 199, pi. 1, 
figs. 0 — 12 (cum. syn.). 
Ter. testa suh-rotunduta seu elongate orata, medio modice dilatata, margine 
frontali in specimitiilms junior ihns simplici sen paulo insiniiato, in adultis plerumqne 
distinctim siniiato ant leviter hiplicato ; valvis fere cequaliter et modice convexis, sen 
valca umbonali alterd paulo conocxiore ; superficie Icecigata, minnte punctata, striis 
ineremcnti nonnullis ad intervalla notata, interdumque radiatim obsolete striolata ; 
umbone modice incurvo, lateribtis phis minnsve acute angulatis seu subcarinatis, 
unguium 1)5“ — 105° formantibus ; foraniine rotundato, minuto seu moderate, labio 
antice plerumqne paulo prodneto, deltidio brevissimo, abrupto, medio sutura vix eon- 
spicua dioiso. 
Tliis well knoAvn species is equally coiiinion aud equally variable in form in the 
South Indian cretaceous deposits, as it is in European strata of the same age. The 
more depressed shell, less prominent and less inemved beak, terminating with a 
smaller foramen, and generally provided ivith rather distinct umbonal ridges, readily 
distinguish the species from T. biplicata, even when the frontal biplication of the 
margin is more distinctly marked than is usually the case. 
Davidson and Schlocnbach (loc. cit.) have discussed the varied relations of 
this species to others at great length, and the latter author also pointed out that 
there does not exist sutiicient reason for separating from Terebratula the species 
with a small foramen, &c., under a sub-generic denomination, fEpithyrix), as suggested 
by McCoy and supported by Deslongchamps. It is not necessary to repeat here 
those statements, but I will brielly note the chief variations under which the species 
is met with in different beds of the South Indian cretaceous deposits. 
As a general distinction I may notice, that there never appear to occur in India 
such short and scmiglobosc forms as are commonly found in England and Ger- 
many, and that in the former, as a rule, tlie beak is not quite as much incurved, as 
usually seen in European specimens. The latter character distinguishes the species 
from T. carnea, with which the depressed and rounded shape of the shell very often 
markedly agrees. Indeed, I am not certain that Davidson’s circular variety of 
carnea (loc. cit., pi. viii, figs. 1 — 5) should not rather be referred to snbrotiuida 
than to the former species. The simple form of the loop and the strong impressions 
of the adductors have been described by Schlocnbach (loc. cit.), and it is sufficient to 
refer here to two figures of the inner views of a hiemal valve, the one having the 
loox) perfectly preserved, the other being an impression with the muscular scars 
(comp. figs. 11 and lla, pi. vi). 
Three varieties may be distingnisbed. The first (see figs. 1 — 6 on pi. vi) has 
an almost cncular or roundly ovate shape, the front is simple or very slightly 
insinuated. The second (figs. 7 — 10) has an ovate or elongate shape, and the frontal 
