492 PROF. F. J. BELL ON THE GENUS ASTERIAS. [May 3 



1. Contributions to the Systematic Arrangement of the 

 Asteroidea. — I. The Species of the genus Asterias. By 

 r. Jeffrey Bell^ M.A.j F.Z.S., Professor of Compara- 

 tive Anatomy in King^s College. 



[Eeceired March 21, 1881.] 

 (Plates XLVII. & XLVIII.). 



The amount of yariation exhibited by the species of the genus 

 Asterias has, as might have been expected, led to the formation of 

 a large number of forms which are at any rate nominally distinct. 

 gr^ Tempting as the work of revision of such a genus ought to be, it has 



never attracted the attention of any zoologist wlio has written on the 

 subject since the time of Miiller and Troschel (1842). The most 

 important and comprehensive work which has appeared is that of 

 M. le Prof. Edmond Perrier, of the Jardin des Plantes. This essay, 

 which was originally published in that still young but already so 

 fertile journal the 'Archives de Zoologie experimentale ' of M. 

 Lacaze-Duthiers, has since appeared separately'. 



M. Perrier's work, though bearing the unambitious title of 

 ' Revision de la Collection de Stellerides du Museum d'histoire 

 r.aturdle de Paris,' is so far extensive in its scope that it contains 

 also a revision of die specimens in the British Museum, and de- 

 scriptions of a number of the new species therein contained. In so 

 far as Prof. Perrier has done his best to get their full value out of 

 the descriptions of Dr. J. E. Gray, which, it must be owned, are 

 peculiarly insufficient and unsatisfactory, and has also been in some 

 cases bold enough to describe new species from single specimens, he 

 has relieved me of two duties, which are always unj)leasant. 



Much, however, as M. Perrier has done with and for the genus 

 Asterias, it would be not proper to pretend to say that he has given a 

 complete revision of the genus : he details only forty-nine species, and 

 does but little to indicate the affinities of the species he mentions, 

 and nothing at all as to resolving them into either natural or arti- 

 ficial groups. 



Nor can the present essay ask to be regarded as any thing else 

 than a tentative eifort in the direction of a complete revision. The 

 collection in the British Museum is still in want of a number of 

 describlid species; while, on the other hand, we must wait for a 

 more perfect monograph till the specimens, which were doubtless 

 collected by the ' Challenger,' and are now being worked out under 

 able hands elsewhere, shall have found their jiroper place in the 

 stores of the national collection. The rich collection made under 

 the supervision of Mr. Alex. Agassiz will soon be described by 

 M, Perrier. 



1 Paris (Eeinwald, 1875). 



