AND ECHIITOTDEi. OP THE E:0REA.N SEAS . 



437 



lat. 32° 49' N., long. 128° 54' E., and measure respectively 7 

 millims. and 11*2 millims. in diameter. 



TEMNOPLErBTJs Eetnatjdi, Agassiz (juv.). 

 1846. Temnopleurus Reynaudi, Agassiz, Cat. rais., Ann. Sc. Nat. vi. 

 p. 360. 



1855. Toreumatica Reevesii, Gray, Proc. Zool. Soc. p. 39. 

 ? Toreumatica granulosa, id., ibid. 



1863. Toreumatica concava, A. Agassiz, Proc. Acad. N. S. Philadel. 



p. 358 [non Gray). 

 18/2. Temnopleurus Reynaudi, J. Agassiz, Rev. Echini, p. 166. 



Coll. St. John : lat. 83° 14' N., long. 182° 55' E., Korea, 40 

 fathoms. 



Very little was definitely known respecting the premature 

 phases of Temnopleurus prior to the careful and characteristic 

 drawings which Mr. Alex. Agassiz has given of this and the pre- 

 ceding species. The present specimens, of a diameter of 9 millims., 

 are distinguishable from young T. Sardwiekii of about the same 

 size by their thinner, more compressed, and subconoid test, which is 

 of a light ashy-grey colour, rayed with pale violet in the interambu- 

 lacral areas. The apical disk is conspicuous, and the primary anal 

 plate very large and characteristic ; the ocular plates are large, 

 with their outer margin tridentiform, and having at the base 

 adjoining the genital plates a lozenge-shaped pit; one ocular 

 enters the anal circle. The interambulacral sutural excavations 

 extend up to the primary tubercle, which has the appearance of 

 standing at the apex of a triangular depression occupying the 

 entire adoral margin of the plate ; the pits are larger and more 

 clearly defined on the actinal than upon the abactinal surface, and 

 those of the median ambulacral area bear on their adoral margin 

 a very large spha^ridia, the series of these, which number six or 

 seven, extending nearly up to the ambitus. There are but very 

 few miliaries upon a plate ; and the two or three which occupy 

 the upper portion still bear traces of fine radial connexions with 

 the primary tubercle. The secondary tubercles, of which, at the 

 ambitus, there is one on either side of the primary, are compara- 

 tively small. 



In young T. Hardwichii of the same size the tuberculation of 

 the plates is distinct and more numerous, and the sutural pits, 

 though deep, are much more limited. 



