OF SOrTITEPtX IXDIA. 
15 
nnterior amhiilacral fuTVOw being one-seventh of the length from the same jioint to 
the anal end ; the apex is central. The iqiper surface is rather finely granular, Imt 
as the granules very easily wear off, it generally ap])ears to he almost smooth ; on 
the lower surface the granules are, however, much more distinct. 
The ambulacra arc very unequal. The anterior ambulacral furi-ow is slightly 
less deep than the others, it is of almost erpxal breadth throughout and deepest at 
the periphery; from the centre to the fascicle arc 10 plates with small rather in- 
distinct pores. One of the antcro-lateral ambulacra has aliout 30 pairs of pores in 
one series, and is very nearly or fully double the length of one of the postero-laterals, 
('ach of which has about 17 pores; the former diverge under an angle of 112 degrees, 
the latter under 02°. The pores in each pair arc connected by a groove, sometimes 
divided longitudinally by a raised line, Avhile the low ridges between each following 
])air of poi’es are granular. 
Forbes in his original description gives the number of pores in the antero- 
and postero-lateral ambulacra as loss numerous ; they were probably taken from a 
smaller specimen than the one figured by him, for in that oue the number corresponds 
with that given above ; the proportions in the number of pores are in both cases 
very nearly equal. 
The same author further states that the ‘ frontal furrow gradually widens 
this is due to an abrasion of the lateral edges near to the periphery ; the furrow is of 
almost equal Avidth throughout in avcU preserved specimens, but it always gradually 
deepens toAvards tbe periphery. 
Loncdilij. — Ootatoor, in a rather sandy, grey limestone. 
Formation . — Ootatoor group. 
7. IIeaiiaster raxa (ForhesJ. PI. II, Figs. 4 — 5. 
187G. Jlrissns rana, Forbes, Trans. Gool. Soc., Loud., vii, p. ICl. 
1855. iremiaaler id., apud D’Orbigny, lAal. Fr.anf. terr- creh, vi, p. 263. 
1858. Feriaster id., apnd llesor, Synop. Boliinid. foss., p. 388. 
“ Flem. ambiln si(b-orb/c?ilari, snh-an(jnlaio, dorso elerato, vcrilce snh-centrali 
(postico*) ; amhidacris prof n.nde hnpressis, anlero-laleralihus lonylorihus lanceo- 
“ latis, poalicAS oralis : sulco aulico profundo, kdo, lateribus sub-declicibiis, inferne 
“ spatio poslorali late oralo. 
Length, l^- inch. Breadth, inch. Greatest height, lj%- inch. 
“ A very tumid sub-globose species, slightly broader than long, and rather 
“ angular in outline. The sides slope steeply. Tlie anal extremity is suddcnlv and 
“ perpendicularly truncate. The anterior and central furrow is rather Avide, and has 
sides Avhich appear to slope, OAving to the rounding of the angles. This furrmv is 
“ not so deep as the latero-dorsal ambulacra. The anterior pair arc lanceolate, and 
E 
* Figura vorticem antero-ccntralein exbibet. 
( 85 ) 
