1900.] ME. E. P. BEDEOBD ON MALAYAN ECHINODEBMS. 277 



distinctly crenulated ia their aboral half, as noticed by other ob- 

 servers ; and, as pointed oat by them, it is of interest in connection 

 with the fossil species of the genus, e. g. Rhabdocidaris nobilis 

 Desor, found in the Upper Jurassic strata of Europe. 



2. Diadema saxatile Linn. (sp.). 



For synonymy, vide S. Loven, Bihang till Kongl. Sv. Vet.-Akad. 

 Handl. Bd. xiii. Afd. 4, No. 5 (1887). 



References. Th. Studer, Monatsber. d. k. Ak. Wiss. Berlin, 

 Oct. 1880, p. 868. P. de Loriol, Mem. de la Soc. de Phys. 

 &c. de Geneve, t. xxviii. No. 8, 1883, p. 13. P. & F. 

 Sarasin, Ergeb. naturw. Eorsch. Ceylon, Bd. i. Hft. 1, 1887. 

 C. Ph. Sluiter, Natuurk. Tijd. v. Ned. Ind. D. xlviii. 1889, 

 pp. 285, 288. G. W. Field, Johns Hopkins Univ. Circ. 

 vol. xi. No. 97 (1892). 



Locality. Singapore and neighbouring islets. 



Habitat. This species is abundant on the reefs wherever the 

 coral is flourishing. In the daytime several individuals may often 

 be seen congregating together under the shadow of projecting 

 platforms of Madrepora, Turbinaria, or other coral. Unlike 

 Drs. Sluiter and Studer, I have never observed it except in the 

 immediate vicinity of living coral and usually on the outer edge 

 of the reef {cf. Field). As the Drs. Sarasin point out, it is an 

 extremely unpleasant creature to handle owing to the sharpness of 

 its spines, the tips of which break off in the flesh, and when any 

 attempt is made to hold it, it generally retreats to a place of greater 

 security ; when in its natural surroundings I have never noticed 

 any indications of attack or defence unless touched. So far as I 

 know, it is the onlv Echinoid which is used as an article of food 

 by the Malays of the " Straits." 



Distribution. The distribution is an extremely wide one 

 throughout both the Atlantic and Indo-Pacific circumtropical 

 zones ; in the north it reaches up to Japan, the Mediterranean, 

 and the Canary Is., and it has been found as far south as the 

 Cape of Good Hope and N.E. Australia, but I cannot find any 

 record of its occurrence from the west coast of America. The 

 species is extremely variable both in form and colouring, but the 

 varieties do not seem to be confined to separate localities. 



In one young specimen the spines, as described by other 

 observers, are banded with purple and white, the test being purplish 

 black as in adult. 



The coloration of this species is subject to a very considerable 

 amount of modification, but whether there is really more than one 

 species living in the district I am unable to state positively. The 

 same uncertainty exists in my mind as to the Asteroid Pentaceros 

 described later in this paper, and it would require a random 

 selection of a large number of examples in order to settle the 

 question. 



Pboc. Zool. Soc,— 1900, No. XIX. 19 



