REPORT ON THE HEXACTINELLIDA. 55 



lie scattered in the soft tissues of Euplectella aspergillum and Euplectella cucumer are 

 described and figured. 



In Max Schultze's well-known research, " Ueber Ilyalonema," published in 1860, 

 there are also some observations on Eu2)lectella spicules. It is interesting to note 

 that Schultze regarded Alcyoncellwn speciosum, Quoy and Gaimard, as identical with 

 Euplectella aspergillum, Owen. The same view was held by Bowerbank, who in 1862, 

 in his third communication On the Anatomy and Physiology of the Spongiadse,' 

 regarded it as indisputable that the older generic name Alcyoncellum of Quoy and 

 Gaimard should replace the name of Euplectella given by Owen. He himself, however, 

 inconsistently employed not the specific designation speciosum but aspergillum. 

 Instead of adopting the generic diagnosis proposed by the French authors, Bowerbank 

 preferred the following summary of the characters of the genus Alcyoncellum : — ■' Sponge 

 fistulate; fistula single, elongate, without a massive base. Skeleton: primary fasciculi 

 radiating from the base in parallel, straight, or slightly spiral lines ; secondary fasciculi 

 at right angles to the primary ones. Oscula congregated, with or without a marginal 

 boundary to their area." 



In his British SpongiadiB (1865), Bowerbank figured and described difi"erent parts of 

 the skeleton of Alcyoncellum aspergillum, Alcyoncellum corbicula, and a new but not 

 minutely described species, Alcyoncellum 7'ohustum, Bowerbank (strictly Alcyoncellum 

 Tohusta)} 



In a short historico-critical paper on Venus' Flower Basket, published in 1868, 

 Gray maintained the identity of Alcyoncellum speciosum, Quoy and Gaimard, and 

 EuplecteUa aspergillum, Owen.^ Since the designation Alcyoncellum was first employed 

 as a generic name for a calcareous Sponge {Alcyoncellum gelatinosum, Blainville) 

 by Blainville, Owen's generic name Euplectella might be preferred ; but the original 

 specific designation speciosa of Quoy and Gaimard should be restored, so that this 

 beautiful siliceous Sponge should in future be called Euplectella speciosa, Quoy and 

 Gaimard. 



In the following year, 1867, Gray described the structure of the skeleton of a young 

 specimen of the same species.* He refers the bent form of the tubes to the presence of 

 Crustacea which appear constantly in the interior. Euplectella cucumer, Owen, is not 

 regarded as a distinct species, but only as a form- variety of Euplectella aspergillum, 

 Owen. 



During his stay in the Philippines Semper had opportunity of examining numerous 

 specimens of Euplectella aspergillum. He questioned the identity of Alcyoncellum 

 speciosum, Quoy and Gaimard, and Euplectella aspergillum, Owen, and wished to 



> Phil. Trans., vol. clii. p. 110.3. = Loc. cit., figs. 257, 258. 



3 Ann. and Mag. Nat. Hist., ser. 3, vol. xviii. p. 487-490. 

 Ann. and Mag. Nat. Hist., ser. 3, vol. xL\. pp. 44, 138. 



