142 PROF. F. J. BELL ON ECHINODERMATA [Feb. 15, 



separates them from the poriferous area ; this last extends down to 

 the edge of the actinal surface. 



On the abaetinal surface there are scattered tubercles and large 

 poriferous patches ; over the whole there is a uniform granulation ; 

 no pedicellarise were detected. 



The madreporic tubercle is large and prominent. 



Colour, in spirit, light yellow, the poriferous patches darker. 



Measurement round the equator 560 mm. ; height 75 mm. along 

 the longest axis. 



The most interesting points with regard to this species are such 

 as bear on its relation to the Echinoidea. Those who accept the old 

 doctrine of Cuvier and Duvernoy, restored in these days by Prof. 

 Haeckel, which explains the constitution of the Echinoderm by the 

 hypothesis that it consists of several fused persons, have found in 

 Culcita the form that seemed to show how the free arms of the 

 Starfish might pass into the compact form of the Urchin. This theory 

 of Echinoderm constitution does not recommend itself to me ; and 

 the present species seems to justify the hesitation which one feels in 

 accepting it. 



While in flattened or irregular Echinoids there is a tendency for 

 the ambulacra to shorten towards the aboral pole, here the tendency 

 is for the shortening to be towards the mouth. In other words, the 

 most extreme Asterid which we know, though it has a remarkable 

 general resemblance to an Echinoid, is, in its essential morphological 

 points, further from it than is a typical Asterid. 



Culcita grex. 



With a little hesitation I refer a single specimen to this species ; 

 the variability of the forms of the genus Culcita is obviously very 

 great, and a careful revision of the species with the aid of a large 

 number of specimens is a pressing necessity. The collection in the 

 National Museum is not yet sufficiently large to justify me in under- 

 taking the task. 



Culcita, sp. 



There are two specimens of what would, a short time ago, have 

 been set down as Randasia granulata. As, however, M. de Loriol 

 has lately shown, the form so called by the late Dr. Gray is really 

 a young stage of Culcita. It will be remembered that Prof. Perrier 

 has expressed himself in a similar sense. Further series are required 

 before the several stages of each species can be accurately defined. 



Echinoidea. 



DiADEMA SETOSUM. 



I am really very doubtful as to the specific identity of two small 

 specimens, the spines of which are banded light and dark, and present 

 the charactersof Dr. Gray's "Ca/?«anMsanwe//«?a," with the adult large 

 black-spined forms which are assumed by D. setosum. However, I 

 have not sufficient evidence to justify me in attempting to refute the 



