Prof. F. J. liell oil a new Species o/" Aiitedon. 427 



Fiij. 2. The tip of atroplionenia, X 42, showing c, the superficial capillary 

 plexus ; tiic otiier letters as belure. 



Fig. 3. Transverse section of a troplionenia in it,s basal half, X 188 ; m, 

 a, V as before ; c, the superficial capillaries of the glandular 

 centre, and c', the superficial capillaries of the non-glandular 

 niavfrin, in section ; (/, a gland in vertical, and (/', one in obliquely 

 transverse section. 



P.S. — Since the above was written I have been fortunate 

 enough to obtain two female specimens of Trygon Bleekeri; 

 in both the left oviduct alone is developed. 



LXIII. — Description of a new Species of Antedon from 

 Mauritius. By F. Jeffrey Bell, M.A. 



[Plate XVIII.] 



The Trustees of the British Museum have lately acquired 

 some specimens of an Antedon from Mauritius which not 

 only appears to be " new," but to present some very inter- 

 esting relations to a group of already known species. 



The group which the late Dr. P. H. Carpenter called 

 (Chall. Kep. Comat. p. 227) the palmata- gvon^) consisted of 

 bidistichate species with an unplated disk and a first pinnule 

 smaller than its successors. 



Of these some have a pinnule on the third brachial, and of 

 those with two or more postradial axillaries some have the 

 rays free laterally. Of these, three species — A. tubei-culata, 

 A. spicata, and A. indica — have the second pinnule stiff and 

 styliform, of twelve to eighteen much elongated joints. 

 With them the Mauritian species is to be placed, but it is 

 to be distinguished from them by the following characters: — 



(1) The marginal projections at the sides of the rays are 



continued on to the most proximal brachial joints. 



(2) The second pinnule, though " stiff and styliform," is 



not extraordinarily so, and the joints, though no 

 more than twenty, are not abnormally long. 



(3) The disk is as small as in A. indica, and the centro- 



dorsal occupies the whole of its aboral siuiace. 



