1880.] 



PaOF. F. J. BELL ON THE TE.MNOPLEURIDJE. 



435 



appended Table will show very clearly that the abacthial, aaal, and 

 actinal areas rather vary in individuals than grow smaller with age ; 

 in this point the species resembles rather Anihli/pneustes than 

 Temnopleurus. The specimens vary considerably in colour, being :n 

 some cases banded with bright red and altogether devoid of a 

 greenish hue ; in another the bands are not purplish, but of a darker 

 green at the base ; in others the base of the spine is not light green, 

 but is of a dark straw-colour. The variations in height are shown 

 by the measurements to extend within wide limits. 



V. Amblypneustes. 



It will still, I fear, be some time before we shall be able com- 

 pletely to "unravel this difficult genus;" and so far as the differ- 

 ence in size of the genital pores is concerned, a new difficulty is 

 almost as much introduced as old difficulties explained. 



I have seen no specimen of A. pentaffonus, A. Ag. If Codechinus, 

 Desor, is really synonymous with Amhhjpneiistes, the genus will differ 

 from all its allies by passing back as far as the Lower Cretaceous for- 

 mations ; for even P/eMrecAf?iMS and Temnechiniis are, so far as we yet 

 know, Tertiary forms \ But Codechinus is defined by Desor as 

 having no angular pores, and it is possible that the two genera are 

 distinct. 



1. Amblypneustes ovum. 



^ ^ Handbuch der Palaontologie (Zittel), i. 3, pp. 507-509, and Synop. des 

 Echinides foss. p. 111. 



This is almost a pentagonal variety. 

 Proc. Zool. Soc— lySO, No. XXIX. 



29 



