OF SOUTHERN INDIA. 
5 
I. Order. CHEILOSTOMATA. 
I sliall use tlio usual nomenclature, cliicily as introduced l)y Busk into tlie 
study of this order. Tire only new term introduc(Hl is tliat of ‘ slitter’, Avitli whicli, 
for brevity sake, I desii^nato those cells which begin a new row or range, and which 
often widely dilfer in size and shape from the ordinary cells. They have l)cen called 
‘ Spaltzcllen’ l)y Ilagenow, because they, so to say, sjdit two parallel rows of cells 
by introducing a third one between them. AVhy these cells should so Avidely differ 
from ordinary cells in some speci(!s of Cellcpora, for instance, and not in others, 
must be settled by the examination of living-specimens. 
Tumihj— CELLEr OTxIEJE. 
Colonies atlached to foreign hodies, inemsting them either in single or numer- 
ous layers, or growing into variously shaped, foliaceous or branched, continuous 
masses of single or double, superposed or oppjosite, layers of cells ; these are flat, 
depressed, or more or less convex and urceolale, generally arranged in alternating 
series, partially or entirely calcareous. 
The extent to Avhich, I think, this family should be accepted, will probably bo 
best indicated when I quote a few names of the most characteristic genera, such 
as Cellepora (=Lepralia auctorum). Eschar a, Celleporaria, ^lembranipora and 
Biflustra. 
I will not repeat the difficulties which as yet appear to have frustrated every 
attempt towards a natural grouiiing of these genera ; time and continuous research 
must gradually clear the path over this stony ground, but if Ave consult our present 
observations on the subject, it seems to me clear that there are chiefly tA\o general 
characters to Avhich Ave can assign any importance in the classification of these genera. 
The one refers to the form of the individual cell, and the other to that of the 
colony, that is, the manner in Avhich the cells are arranged during growth by 
gemmation. 
As regards the first point, obseiwations shoAV us that there is, as a ride, a 
tolerably defined distinction between an urceolato and tlustrine cell, the former being 
typified by an ovate shape, Avith the front, or upper, siuTace of the cell moderately 
conAmx, with a comparatively small aperture situated near or at the anterior end, 
and mostly surrounded by a slightly thickened lip. The tlustrine cell, on the other 
hand, is flat above, often siuToundcd by a raised margin, and Avith an anterior 
sub-terminal or central apertm^e, generally of large size. IIoAveA'er, there are cases 
to be met with in Avhich it is not easy to maintain this distinction, — namely, Avhen 
the upper surface of the tlustrine colls becomes Avholly calcareous and thickened 
and shghtly arched, narroAV'ing the aperture, and Avhen the surrounding ridges are 
only partially developed, or almost obsolete. As an example of this kind I may 
cite, for instance, d’Orbigny’s Cellepora Xiphia from the cretaceous deposits of 
France. Still even accounting for a large amount of variation, and a great number 
( 39 ) 
B 
