248 MR. H. L. CLARK ON SOME 
Ophioplocus IMBRICATUS. 
OpMolepis imbvicata Miiller & Troschel, 1842, Syst. Ast. p. 93. 
Ophioplocus imbficatus Lj-maii, 1861, Proc. Boston Soc. Nat. Hist. viii. p. 7'J, footnote.. 
There are two adults, light-coloured specimens oi: this species in the 
collection, taken- on the reef at Long Island, Pelsart Group. 
ECHINOIDEA. 
Peionocidaeis baculosa var. annulifeea. 
Cidarites annulifera Lamarck, 1816, Anim. s. Vert. iii. p. 57. 
Prionocidaris baculosa var. anmdifera Mortensen, 1918, Kunpfl. Svenska Vetensk. 
Handl. Iviii. no. 9, p. 8. 
A very fine specimen of this handsome sea-urchin was dredged among the 
islands of the Wallaby Group. It is 49 mm. in horizontal diameter, and the 
largest primary spines, which are all more or less conspicuously banded with 
reddish-purple and greenish-yellow^ are about 57 mm. long and 5 mm. in 
diameter near the base. The number and arrangement of the conspicuous 
red-purple spots on the collar of the primaries show great diversity. 
Prionocidaris bispinosa var. chinensis. 
Dbderlein, 1903, Jena Denkschr. viii. p. 697. 
A small cidarid dredged off Long Island resembles so closely Doderlein's 
description and figure that I refer it to this variety with little hesitation, even 
though the type-locality is so far distant from the Abrolhos. The specimen 
is 35 mm. in diameter. Most of the primary spines are broken or missing,, 
but the unspotted red-brown collar is characteristic, and the distinctive 
thorns are well-developed on the upper spines. The longest ones, 33 mm^ 
long, 2 mm. in diameter at the collar, cylindrical, and without thorns, are at 
the mid-zone. The secondary spines are brownish-red, those on the ambulacra 
being slightly darker than those on the interambulacra and with a purplish 
tinge. 
Centrechincs savignyi. 
Diadema savignyi Miclielin, 1845, Rev. Mag. Zool. p. 15. 
Centrechinus saviynyt H. L. Clark, 1921, Echiiioderm Fauna of Torres Strait, p. 145. 
A specimen 85 mm. in diameter was taken in the shore-collecting at 
Wooded Island. 
Centrechinus setosus. 
Echinometra setosa Leske, 1778, Add. ad. Klein, p. 36. 
Centrechinus setosxs Jackson, 1912, Phylogeny of Echini, p. 28. 
A specimen 80 mm. in diameter was taken during the shore-collecting in 
the Pelsart Group. The abaetinal white spots are large and conspicuous, and 
easily distinguish the species from the preceding. 
