40 
CRETACEOUS ECHINODERMATA 
and there arc besides on the miliary zone numerous very small granules, again 
differing in size among themselves. 
In structure, namely, the number and form of tubercles on the ambulacral and 
interamhulacral zones, the present species rather closely resembles the well known 
Salenia scutigera, Gray, hut differs from it, and, as far as I have been able to make 
comparisons of figures and descriptions, from all other known species by the com- 
paratively small height of the test, the large broadly conoid disc, and the wide 
mouth. 
LocMity. — Comarapolliam, in a coarse sandstone; only the figured specimen 
was examined. 
Formation . — Arrialoor group . 
Family,— ECUINIDyF. 
Comp. Cotteau, Pal. Frau5. terr. cret., vol. vii, p. 808. 
The Echmidee, as originally defined by Wright, and afterwards restricted by 
Cotteau, include a large portion of the Latistellate group of the old family Cibaribje. 
They have a rather spheroidal test ; their ambulacral areas vary in width, and each 
plate, as also those of the interamhulacral areas, is provided with several comparatively 
small primary tubercles, these being perforate or imperforate, and with the upper 
edge of the bosses crcnulated or smooth ; the poriferous zones have the pores in 
pairs, or in more numerous series, and always more or less irregular. Mouth of 
moderate size, the margin with ten incisions. Ruccal membrane naked, or covered 
with small scales, irregularly arranged. Anus central, situated between the five genital 
and five ocular plates, one of the former being united with the madreporiform plate. 
Spines mostly short, subcylindrical, or subulate, generally marked Avith fine longi- 
tudinal, suhgranular striae. 
When compared with the Cidarij)^ the members of the present family ai’e 
easily distinguished by the width of the ambulacral areas and the development of 
distinct primary tubercles on them, as also by the incisions of the apertural margin. 
The difference is, how'ever, much less pronounced between the Eciiinidm and 
the Bjadematidm, particularly in those divisions in wdiich the primary tubercles 
on the ambulacra are comparatively small and numerous, and wRere the poriferous 
zones arc multigeminal, but even in these fcAV very closely related genera, the 
Eohixie^ show, as a rule, a more marked irregularity in the relative position of the 
pores. 
Cotteau divides the family into two groups, according to the tubercles being 
(1) perforated or imperforated, with the bosses crenulated, or not perforated and 
crenulated, or (2) with the tubercles neither perforated nor crenulated. Of the 36 
genera of AvRich abbreAuated characteristics are given, only one occurs in South 
India, and is represented by a single species from the ujApermost cretaceous beds. 
( no ) 
