OF SOUTHERN INDIA. 
35 
Famihj—i: CHINO CONIBJE. 
D’Orbigujj Pal. Frang. terr. cret., vi, p. 4.j9, and Cotteau, ibidem, tome vii, p. 10. 
Galehitid.^, auetorum, ex-parte. 
This family, as dcQiiecl by Wriglit, Cotteaix, and more recent authors, adopting 
in part d’Orhigny’s views on the subject, includes Echinoids of moderately large 
size, circular or pentagonal, hemispherical or conoid in shape, the lower surface being 
flattened or concave, and the upper more or less elevated ; the entire surface is covered 
with rather small, perforated, crenulated or smooth tubercles, and intermediate very 
fine granules ; the apex and mouth are central, or jiearly so : the former composed of 
five genital and five ocular plates, the genital plates being either all perforated or the 
posterior impair one is smallest, imperforate, rarely obsolete ; the mouth is on the 
lower side, round, or decagonal, with slight incisions and internally provided with 
jaws; ambulacra nai’row, continuous from the apex to the mouth, composed of very 
small, equal pores ; interambulacra broad. The position of the anus is very variable, 
always eccentric, either on the upper or on the loAVcr side, or sub-marginal. The 
spines are generally small and thin, longitudinally sulcatcd. 
Cotteau {1. cit.) restricts the family to six genera, Fchinoconus, Discoidea, 
Ilolecty^nis, AnoHhopyyiis, Fileiis, and Fygaster, all of wliich are extinct, occurring 
in jurassic and cretaceoxis deposits. Of these only Echinocomis with two and Ilolec- 
typus with one species find representatives in the South Indian cretaceous deposits. 
The closely alRed Nciiijsojstadje, of which the typical genera Ecldnoneus and 
Pyrina were by d’Orbigny also referred to the present family, and of which some 
forms are still foimd living, differ by their mostly somewhat elongate or ovate shape ; 
the apical disc is composed of only four genital plates, the peristome is mostly utc- 
gularly pentagonal wdthout incisions, and there are no jaws present. The only other 
allied family are the Collyritivje or Bysasteridas, the members of which have an 
elongate apical disc, the ambulacra meeting at two points ; theyalsohaveno jaw's, and 
the mouth is eccentric. 
Some of the Bciiixocoxid^e show in external shape a very marked resemblance 
to the Bchixid^, both in form and ornamentation of the test, and in the central posi- 
tion of the mouth with its incisions in the peristome. 
X. Genus. — ECIIINOCONUS, Breynhis, 1732. 
D'Orbigny, Pal. Frany. terr. eret., vi, p. 496. 
Galeriles, Lamarck et auetorum. 
Test of moderate size, hemispherical or conoid, covered with small, submammil- 
lated, crenulated and perforated tubercles, intermediate space finely granular ; apex 
subcentral, composed of fom perforated and one (the posterior) smaller and imper- 
forated genital, and five ocular plates ; ambulacra radiating from the apex, continuous-, 
the pores in each pair very close to each other ; apertm-e central or very nearly so, 
decagonal ; anus marginal or interiorly sub-marginal. 
K 
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