37 
Fam. 6. ECHINOMETRAD. 
Ambulacral area ouly half as wide as the interambulacral area ; 
ambulacral pores in groups of four or more, forming an arched series 
round the ambulacral tubercles. 
A. Body circular. 
1. Strongylocentrotus. Spines equal, subulate, short. 
B. Body oblong. 
2. Echinometra. Spines subulate, subequal. 
3. Holocentronotus. Spines of back elongate, subtriangular; of 
the oral side large, spathulate. 
4. Colobocentrotus. Spines of the back very short, truncated ; of 
the oral side spathulate. 
Dr. Gray described the following species, which he regards as new, 
from the British Museum Collection. 
Genus CrparRIs. 
* Spines smooth or granular. 
1. CrpaRis ORNATA. 
Depressed. Tubercles of interambulacral area rather distant ; 
spines lanceolate, subulate, depressed, white, red-ringed ; base with 
series of small red spots, and with regular longitudinal series of gra- 
nules; each side with one, and the upper surface of the base with two 
series of white angular spines; spinules white, with a central red 
streak. 
Hab. East Indian Seas. 
** Snines verticillate-spinose. 
2. CiDARIS VERTICILLATA. 
Depressed. Interambulacral tubercles rather far apart ; spines of 
upper surface rather elongate (about as long as the diameter of the 
body), subulate, smovth; some subulate at the top, others with 
scattered conical spines, others obliquely truncated, cupped, and 
spinose at the tip; spines of lower surface shorter, cylindrical, trun- 
cated, granular near the tip ; those of the oral surface much spotted, 
truncated, compressed and largely granular near the end. 
Hab. 2 
3. CrpaRIS ANNULATA. 
Orange. Rather depressed. Interambulacral tubercles of moderate 
size, far apart; spines elongate, subulate, tapering, red and white 
ringed ; suprabasal ring white; with longitudinal ridges. The ridges 
of the lower half of the spines spinulose and with scattered larger 
spines; sometimes placed in lines. The dorsal spines sometimes 
truncated and slightly cupped at the tip; ambulacral spinules nar-. 
row, flat. 
Hab. West Indies. 
