OF SOUTHERN INDIA. 
11 
Milnc-Edwards and llaime united d’Orhigny’s Aplocyathns with the present 
^•enus, and Eroinentel (1. c., p. 174*,) states that Varcicijailius is not separable from 
the same, as it only differs hy a somewhat large base and a few minor points in the 
structure of the pali and the columdla. 
The Ti'ochocyathi are found from the middle Jurassic period up to the present 
time ; they appear to have been most numerous, however, in the tertiary period. 
All the cretaceous species, seven or eight, as yet known, have their costse granulated, 
not spinose. 
Only a single species of the genus has been met with in the Ootatoor beds of 
Southern India. 
Tkociiocvatiius affinis, StoUezka. PI. I, Eig. 19. 
Trochocy. corallum cnpul'iforme, latius quam altum, basi obtuse conoideum, 
liberum, s^lperf,cie costatum, costis ineequalibus, granulatim ruyulosis ; seplis supra 
acutiusculis, in qninqne cyclis — quatuor perfeetis, quinto imperfeoto — dispositis, later- 
aliter yranulatis ; path virciter 32, valde ineequalibus, nonnunquam subrectis atque 
incequaliter inerassatis ; columella lata, lamelUs sex, contortis atque conjluentihus 
composita. 
A small cupuliform species, very closely allied to Troeli, Ilarveyanus, Milne- 
Edwards and llaime, from the English Gault, but differing from it hy a fifth im- 
perfect cycle of septa, and hy thiunei*, more irregular aiid more numerous pali. The 
costye corresponding to the first three cycles and half of the fourth cycle differ 
very little in thickness, hut the remaining are very much thinner ; all are very 
finely and somewhat iri-egularly granulated. The mural theca is somewhat 
thickened at the base, hut there is no plaee of attachment traceable on the latter. 
Locality. — West of Kurribiem, in a yellowish calcareous sandstone ; a single 
s))ecimcn was met with. 
Formation. — Trichinopoly group. 
III. PLATYCYATIIUS, Fromentel, 18(51. 
Pal. Praii9. terr. cret., I8C3, tome vili, p. 180. 
Corallum discoid or sub-discoid, with the mural theca only horizontally or 
basally developed and generally smooth ; septa numerous, laterally, sharply granu- 
lated, arranged in six systems ; pali numerous, uneqttal ; columella large, composed 
of numerous twisted sub-cylindrical columns. 
This genus was jiroposed by E’r omen tel for Milne- Ed wards and Haime’s 
Trochocy athus Terquemi, differing from the true Trochocyathi by tho mere hori- 
zontal or basal development of the mural theca, while higher up the septa remain 
freely exposed. Although this difference appears to be only a slight one, Ero- 
mentel believes it to he in conformity with the generally adopted classification, 
( 143 ) 
