184 
OOLITIC ECHINODERMATA 
Genus 25. — Goniaster, Agassiz (Vol. II, p. 106). 
Body pentagonal, only slightly produced, flattened on both sides. Margins bounded 
by two rows of granulated plates, always larger than the remaining ossicula. Two 
rows of ambulacral pores. Range of genus from Lias to existing period. Two British 
Oolitic species (Vol II, pp. 108, 109). 
Ge7iu8 26. — Stellaster, Gray (Vol. II, p. 164). 
Body pentagonal, angles produced, rays tapering. Marginal plates thick, finely 
granulated. Lower marginal plates bearing spines and granules. Upper and under 
surfaces, apart from the marginal plates, covered with small polygonal ossicles, smooth 
and granulated. Ambulacral furrows narrow, with two rows of ambulacral pores. Anal 
opening subcentral. Range of genus from the Oolitic to the existing period. One 
British Oolitic species (Vol. II, pp. 165, 166). 
Family XIII.— ASTROPECTINIDiE, Muller and Troschel (Vol. II, p. 110). 
Body stellate, flattened on both sides, rays five or numerous, narrow, elongate, and 
bordered, sometimes by an upper and sometimes by an upper and an under series of 
large conspicuous plates. Lower marginal plates always spiniferous ; upper, when 
present, granulated and spiniferous to a greater or less degree. Upper surface, apart 
from the marginal plates, covered with closely-set paxillse ; under surface crowded with 
short spines arranged in regular rows. Ambulacral furrows narrow. Two rows of 
ambulacral pores. Separate anal opening absent. Family ranging from the Lias to the 
existing period. Represented in the British Liassic and Oolitic strata by three genera 
(LuiDiA, Plumaster, and Astropecten) and fifteen species. 
Gems 27. — Luidia, Tories (Vol II, p. 110). 
Body stellate, covered on upper surface with paxillse ; disc comparatively small ; 
rays variable in number, sometimes numerous, elongate, provided on under surface wdth 
a single row of marginal plates, carrying at the central portion short thick spines, and at 
the margin long recurved spines. Ambulacral furrow uarrow. Tw^o rows of ambulacral 
pores. Range of genus from the Lias to recent period. One British Liassic species 
(Vol. II, p. 111). 
