OF SOUTHERN INDIA. 
45 
The alternating position of the pairs of pores on the upper side, and the rather 
large opening for tlie apical disc, clearly indicate that the species belongs to the 
present genus. The general form and ornamentation exhibit a great resemblance 
to those of Ps. 2 )seudo-ornatum, Cottcan,* from the Cenomanien. The primary 
tuljercles form only two rows on both the ambulacral and interambulacral areas, 
and are about equally strong, and both below towards the mouth as well as above; 
towards the apical disc they very much diminish in size. The areolse are large 
and smooth in both cases ; each ambulacral plate has the areola surrounded by a 
row of sub-equal granules, while on the interambulacral plates these granules are 
more numerous aird of three sizes, the largest on the outer side, approaching to 
form a row of secondary tubercles. 
I have given three views of the fragmentary specimen Avhich may he of 
assistance in a subsequent search after this interesting fossil. 
Locality. — Mulloor, in a coarse, almost conglomeratic sandstone. 
Formation. — Ai-rialoor group. 
A second, also an imperfect specimen, is from the Ai’rialoor sandstone near 
Arrialoor. It evidently belongs to a species distinct from the previous, differing 
from it by comparatively larger primary tubercles, which arc equal on the ambulacra 
and interambulacra, by a somewhat smaller oral opening and by more distinctly 
undulating poriferous zones. It is possible that tliis specimen may belong to 
Ilemiciclaris, but much better materials are required to ensure even a reliable 
generic determination. Comp. figs. 1, 1«, on FI. VII. 
XV. Genus. — ORTIIOPSIS, Cotteau,- 1863. 
Pal. Fran 9 . terr. cret., vol. vii, p. 550.. 
Test of moderate size, somewhat depressed, poriferous zones narrow, with the 
pores throughout in simple, regular pairs, each two pores in a pair separated by a 
granular elevation. Primary tubercles in two or more series, and of sub-equal size 
on the ambulacra and interambulacra, with granules between them, as in Psendo- 
diaderna ; they are also perforated, but the bosses are not crenulated on the upper 
edge. Aperture rounded, with distinct incisions on the margin. Anus somewhat 
irregularly rounded, of moderate or small size, surrounded by the granular plates of 
the apical apparatus. 
Cotteau refers fom’ species to this genus, all from cretaceous beds, to which 
Orthopsis appears to be restricted. The regularity of the pores and the smoothness 
of the bosses readily separate the genus from Psettdodiadema. 
* Pal. Fran?, terr. cret., vol. vii, pi. 1116, figs. 5 — 15. 
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