1881.] 



PROF. F. J. BELL ON THE GENUS ASTERIAS. 



507 



69. polaris. 



60. poljplax 



61. rarispina 



62. rodolpbi 



63. rubens 



64. rugispina 



= \/ 2 maa'. 

 = V '2 pat. 

 - 1 atr. 



= V 1 mat. 

 = 2 ats. 

 = 1 atr'. 

 6.5. rupicola (?) = 1 atr. 



66. scabra — s/ 2 maa'. (?) 



67. sertulifera = 1. 



68. siuusoida = 2 e. 



69. spectabilia 



70. stellionura 



71. studeri 



72. sulcifera 



73. tenera 



74. teuuispina 

 7.5. troscbeli 



76. vancouveri 



77. varia 



78. vulgaris 



= 2e. 



= 2 aa'. 



= V 2 mat. 

 = 2e. 



= 2 ate. 



= V 1 j}aa'. 

 — 1 atr'. 



= V 2 mat. 



= 1. 



= 2 ats*. 



Characters of Leptasterias, Verrill. — It may well be a fair question 

 to ask, why, when a genus contains so many species, I do not avail 

 myself of Prof. Verrill's generic division oi Leptasterias. The answer 

 falls under two heads : — First, the leading distinctive character is the 

 comparatively large size of the papulae ; but this is only a step from 

 •what we find in species that are still retained in the genus Asterias 

 proper ; the presence of a circlet of spines around the madreporic 

 plate is certainly not a characteristic of the Leptasteriads alone, as 

 must have been abundantly shown in the earlier part of this paper ; 

 while, further, all specimens of A. muelleri are most certainly not 

 echiuoplacid. In the second place, the presence of a large number 

 of species in a genus cannot, of itself, be any reason at all for esta- 

 blishing a number of insufficiently distinct genera. Queri libet de 

 natura : ita est. For the purposes of descriptive systematic zoology 

 it may be, and is, necessary to break up an enormous genus into 

 smaller convenient working groups ; but it is better not to give to 

 such groups titles which have a precise technical value. 



For the present, at any rate, I think we may retain Gray's genus 

 Uniophora. 



Characters of the Species of Asterias found in the 

 Britjsh Seas. 



My attention was more particularly directed to this subject by the 

 difficulty which I had in coming to any distinct idea as to the 

 characters of A. hispida. Unable to distinguish any forms as such 

 in the cabinets of the British Museum, I naturally turned for assis- 

 tance to the well-known naturalist whose acquaintance with the 

 marine fauna of our own coasts is only equalled by his kindness and 

 courtesy. To the Rev. A. M. Norman, then, the national col- 

 lection owes some specimens of what he distinguishes as A. hispida. 



In addition to the specimens of ^. hispida which he presented to 

 the Museum, Mr. Norman sent for my inspection several other 

 series of specimens from various localities. In the letter with which 

 he honoured me, Mr. Norman hinted that A. hispida and A. violacea 

 should now be united, he expresses some little doubt as to the accu- 

 racy of the determination of the specimens collected in the British 



* [To make this paper as complete as may be, I add a reference to the species 

 (^A. S2>itiibcrffcnsis) lately described by Messrs. Danielssen and Koren. It ap- 

 pears to be peiitactinid, ]5olyacanthid, and echinoplacid. See Ann. Nat. Hist. 

 (5) viii. p. 66.— F. J. B. July 1st, 1881.] 



33* 



