from Japan and the Indian Ocean. 89 



dislinguislied from all known members of the genus lies in 

 the peculiar arrangement of tiie primary tubercles," says 

 Yoshiwara. In A. varium, however, the arrangement of the 

 primary tubercles is very similar (coinp. fig. 2 a, ])1. 50, of 

 Doderlein, '^ Echinoidea von Amboina und Thursday Island^'' *). 

 The essential distinguishing characters of this very distinct 

 species are found in the pedicellariaj and spicules, and the 

 non-ringed primary actinal spines. Tiie little developed, not 

 annularly constricted bag of skin on the abaci inal sj)iues is au 

 additional, though probably less reliable, character. 



A. ijimai in its general appearance resembles the other 

 species of the genus, with the conspicuous covering of tiie 

 abactinal side by close-set, ringed, almost equally sized, skiu- 

 clad spines. 



3. Calveria gracilis (Ag.). 



Asthenosonia gracile, Agassiz, 1881, 'Challenger' Echinoidea, p. 89, 



pi. xvii. a. figs. 1-4. 

 Asthenosoma lonc/isjmium, Yoshiwara, 1897, op. cit. p. 5, pl.ii. figs. 1-7. 

 Ca'veria gracilis, Th. Mortensen, 1903, 'In>>olf' Ecliinoidea, p. 51, 



pi. xiii. fig. 3 ; de Meijere, 1904, ' Siboga ' Echinoidea, p. 34, Taf. xiii. 



tig. 152. 



I'he " Asthenosoma longispiniim " of Yoshiwara so closely 

 agrees with Calve) ia gracilis [A g.) that 1 cannot find a single 

 character by which to distinguish it from t'lat species, with 

 Mhich, accordingly, it must be regarded as synonymous. It 

 is only to be remarked that in the type s]jeciinen of Agassiz 

 some violet patches are found on the actinal side, which is 

 not the case in the s| ecimens before me. The colour is dark 

 red, almost claret-coloured ("vinosus'^j in the one specimen, 

 rather pale, but of the same tint in the other. 



This species is very closely related to C. hystrix ; the only 

 distinct difference 1 can find is the colour, which is al\va}s 

 beautifully red ('^ ruber") in C. Jiystrix. The tubercles of 

 the outer iiiterambulacral plates of the actinal side are rather 

 more numerous than in hystrix, as pointed out by Agassiz, a 

 rot very prominent feature. In the pedicellarias no distinct 

 differerices are found. The chief peculiarity, indeed, lies in 

 the geographical distribution of the two species. If both 

 were fuund together they would certainly be regarded, at most, 

 only as varieties of one species. 



To the description given by Yoshiwara a few corrections 

 must be made. The larger of the primary ambulacral plates 

 are stated to "consist of three pieces apposed together in a 



* Sen:on's ' Fcrschungficiion/ v. 1902; Jen. Denlcschr. viii. 



