OF SOUTH EllX INDIA. 
37 
slightly produced, tliati towards the anterior end. The lower side is flat, witli fine 
grooves indicating the” ])orifcrous zones, the pores in them being so small as to be 
hardly distinguishable. The mouth is rather larger and the anus more marginal, 
and more distinctly indicated in an upper view than in any other species known. 
LomUhj. — Karapaudy, in a whitish coarse sandstone ; only the figured s])eei- 
men has been examined. 
Fo rmailon . — Arrialoor group. 
XI. nOLECTYPUS, Besor, 1842. 
Desor, Synops. Echiu. foss., 1858, p. 168. 
Cotteau, Pal. Franc;, terr. cret., vol. vli, p. 42. 
Test of small or moderate size, discoid or roundly pentagonal, upper side 
convex, highest at the apex, which is central, lower convexly flattened, concave 
towards the centre, in which the mouth is situated ; the latter is decagonal, with two 
incisions in the margin of each intcrambulacrum and tvith jaws internally ; 
tubercles of the surface small, perforated, crcnulatcd, with intermediate granules ; 
apex composed of five ocular and five genital plates, the anterior right is, as 
usually, largest and madreporiform, the posterior plate is sometimes imperforated 
and smaller than the rest ; ambulacra continuous, composed of very small closely 
set pores in oblique pairs ; anal opening ovate or pyriform, inferiorly marginal, 
very large, with a simple margin ; spines small, marked with longitudinal strim. 
Uolcctypm is an enthely extinct genus, occurring in Jurassic and in cretaceous 
rocks, the species being more numerous in the former than in the latter. It is very 
closely allied to Biscoidea, dilfering from it by the absence of any internal ridges 
at the periphery, and by having the anal opening mostly of a largo size. All the 
cretaceous species have the apical disc composed of five perforated genital plates, 
while in the Jurassic species only four are perforated, and the hinder impair one 
small and imperforated, or sometimes almost obsolete. 
There are ten species of Uolectypus known from cretaceous deposits. 
1. IIoLECTYPtrs sp. indet. PI. VI, Fig. 5. 
The single specimen does not admit of a good characteristie being given, but 
it seems to belong to an undescribed species. The test has greatly sufl'ered from 
lateral pressure, but the general form very closely approaches to that of 
II. C7'assus seriulis, (compare Cotteau, 1. cit., pp. 55 and 59, pi. 1017). The 
Indian fossil seems to be slightly less elevated than the former, but slightly more than 
the latter, the granulations of the surface and the Avidth of the ambulacra agree l^etter 
with serialis, the mouth appears to be, however, wider than in either of the two. 
( 107 ) 
