436 



PROF. F. J. BELL ON THE TEMNOPLEURID/E. [Juiie 1, 



It is with some hesitation that I inckide in this rather unsatisfac- 

 tory series the first and second examples, the great difficulty in the 

 way of associating them with the larger specimens being the much 

 greater proportional size of the tubercles on the test ; other forms, 

 however, present just the same relation, and the difference in tlie 

 proportional size of the tubercles in examples iii. and vii. is itself 

 sufficiently striking. 



Two of the specimens in the Museum collection are stated to have 

 been collected at the Cape of Good Hope. The test is sometimes 

 reddisli or purplish in colour, and it is not always that all the ocular 

 plates are shut off from the anal area. 



2. Amblypneustes griseus. (Plate XLI. figs. 4, 5, 6.) 

 The Table just following shows that there is a considerable varia- 

 tion in the pro])ortions of the species ; it will, however, be pointed 

 out that these differences are associated with others which led to the 

 possibility of their being diflerent sex-forms. In any case, it is, 

 without a large series of specimens, impossible to see fully how these 

 differences run, and I am convinced that no good would be gained 

 by attempting to affix distinct names to the two forms. Younger 

 specimens than have yet come to hand will resolve some of the 

 difficulties, and an examination of living specimens will do even 

 more. 



It does not require much observation to see that these measure- 

 ments point to two distinct series of proportions among forms which 

 by the other characters of their test appear to be most intimately 

 allied : one series, represented by xi., x., viii., and vi., have a 

 small actinostome, a small abactinal area, and a rather wide pori- 

 ferous zone ; the other, as seen in ix., vii., iv., has the actinal 

 and abactinal areas very much larger and the poriferous zone rather 

 narrower. With these characters two others, that cannot be repre- 

 sented in the Table, are associated ; those with the small actino- 

 stome have much larger genital pores, and the madreporic plate is 

 much more prominent. I hesitate, however, to separate them, for 



