]00 " ENDEAVOUR " SCIENTIFIC RESULTS. 



Twenty-five miles south-east of Double Island Point, 

 Queensland. 



Eleven miles south-east of BalHna, New South Wales, 27- 

 29 fathoms. 



Genus Cidaris, Leske. 



CiDARIS CONFERTA,! Sp. nOV. 



(Plate xxxviii., fig. 1-4.) 



Test Httle flattened ; vertical diameter about .60-. 70 of 

 horizontal ; coronal plates 7 or 8 ; areolae large, nearly 

 circular, only the lowest 2 or 3 confluent ; median interambu- 

 lacral area with vertical suture quite distinct and 3-4 series 

 of tubercles on each side of it ; ambulacra about one-fourth 

 of interambulacra in width ; poriferous zones not sunken, 

 very narrow, the pores close together ; median ambulacral 

 area with a double series of tubercles on each side, inner much 

 smaller ; vertical suture not very distinct ; pores large, nearly 

 circular, only shghtly oblique. Abactinal system about .46 

 of horizontal diameter of test, nearly circular and clearly 

 defined, flat or slightly elevated, well covered with small 

 secondary spines ; genital plates large and nearly square, 

 outer margin a little convex and inner equally or more 

 concave, with pores near distal margin ; ocular plates tri- 

 angular or with inner angle truncated when plate is fully 

 insert, as wide as high or wider, with pores very close to distal 

 margin ; in four specimens oculars I, V and IV are insert, 

 while in the largest specimen all are insert, though IV is very 

 narrowly so ; anal system about one-half diameter of abac- 

 tinal system, covered by a marginal series of 8-10 rather large 

 plates and 12-15 (or more) smaller ones within ; all abactinal 

 and anal plates are fairly covered by rather coarse tubercles ; 

 there are 2-10 on the anal plates, 30 or more on the oculars, 

 and 50 or more on the genitals. Actinostome small, only 

 about .37 of horizontal diameter of test, not at all sunken, 

 closely covered by stout plates, 12-15 in each interambu- 

 lacrum and about a dozen pairs in each ambulacrum. Pri- 

 mary spines when fully grown 60-70 mm. long, and 2.5-3.5 mm. 

 thick, cylindrical and tapering rather abruptly to a bluntly 

 pointed tip ; in the largest specimen they are distincly com- 

 pressed near tip ; except when still immature, they are very 

 closely covered by low, rounded granules, which are so closely 

 crowded they do not form longitudinal series as is usual ; the 

 collar is very low, about 1-1.5 mm. high, very finely striate 



1. Confertus=cTovrded ; in reference to the densely crowded granules 

 on the primary spines. 



