OF THE SPONGIAD^B. 175 



the exquisite beauty and regularity of the texture of the 

 walls of the cone, the species surpasses any of the allied 

 productions that I have yet seen or found described. I 

 propose, therefore, to name it Euplectella aspergillum." In 

 note 5 appended to this paper, Professor Owen also says, 

 " If the recognition of the generic or specific identity of 

 the specimen here figured be impracticable by reason of 

 its mutilated condition, the generic name applied to it 

 cannot be adopted while the Lamarckian genus of fresh 

 water polyps, Alcyonetta, is retained in Zoology." Now as 

 it is manifest that the reasoning of Professor Owen in 

 favour of his proposed genus Euplectella is based, not upon 

 one only, but upon a series of errors, and as he has not 

 attempted to characterise his own genus, while that of 

 Alcyoncellum, Quoy et Gaimard, is regularly described in 

 the ' Histoire Naturelle des Aniuiaux sans Vertebres ' by 

 Lamarck, 2nd Edit., vol. ii, p. 589, printed in 1836, it is 

 evident that the generic name of the French authors must 

 take precedence of that proposed by Professor Owen. 



The following is the generic description of MM. Quoy 

 et Gaimard : 



" Genre ALCYONCELLE (Alcyoncellum). 



Spongiare, lamelleux, dont la charpente est formee de filets 

 tres delies, accoles les uns aux autres et entre croises 

 de maniere a former des mailles nombreuses, arron- 

 dies, assez regulieres, et semblables a celles d'une 

 dentelle." 



In this generic description the material of which the 

 sponge is formed is not in the slightest degree indicated, 

 and the description of its structural peculiarities is so 

 general that it will apply equally well to almost every 

 known fistulose sponge. I have therefore thought it neces- 

 sary to arrange the sponges of this genus with their con- 

 geners in material and mode of construction, and to recon- 



