308 THE VOYAGE OF H.M.S. CHALLENGER. 



On the Portuguese coast Gwyn Jeffreys also found A'phrocallistes hocagei. 



Carter, in bis system of the Hexactinellidse, ^ unites the characters which are common 

 to the two then known species of Aphrocallistes in the following manner: — "Species 

 tubular branched, branches closed at their free extremities, wall thick, formed of 

 polyhedrally reticulated fibre possessing a scopuline shaft." 



Of Aphrocallistes heatrix, Gray, he says : — " Rosette (small) with elongated shaft-like 

 axis, many-rayed, rays straight, pointed or capitate, thorn-like chiefly situated in the 

 middle and at the terminations of the shaft, arranged more or less verticillately ; or 

 (large) with microspined rays slightly curved and not capitate. Scopuline shaft headed 

 with four rays of equal length, slightly everted, microspined, and terminating in small 

 globular heads." 



With respect to Aphrocallistes hocagei, Wright, on the other hand, he notes the 

 following as peculiar : — " Rosette many-rayed ; rays of equal length, straight, capitate ; 

 or with long shaft-like axis, like that of the small form in Aphrocallistes beatnx, with or 

 without heads. 



" Scopuline shaft headed with four rays of equal length flexed outwards, e7i fleur-de-lis, 

 microspined, and each terminating in a large conical end." 



In the more minute description^ given of the two species, which are especially related 

 by the form of the spicules, Carter notes the following different spicular forms as being- 

 characteristic of Aphrocallistes hocagei : — 



(1) " Linear fusiform spicules with inflated centre and extremities. 



(2) " More delicate linear fusiform spicules, spiued throughout, all the spines being 

 in the same direction. 



(3) " Hexradiate spicules whose arms are more or less unequal in length, five being 

 smooth at the commencement and conieally inflated and spined at the termination, and 

 the sixth spined, feather-like, rounded, the spines increasing in length from the fixed 

 end to the free. 



(4) " Scopuline spicules, consisting of a long shaft and four rays terminating iu 

 conical heads surrounded by recurved spines. 



(5) " Rosettes with five-rayed capitate arms. 



(6) " The same rosettes with the axis stretched out linearly, shaft-like, and the rays 

 arranged round it more or less spirally. 



(7) " The same rosettes, with the rays of the shaft more confined to its centre and 

 all simple (that is, not capitate, but pointed)." 



In Aphrocallistes heatrix, Carter found the spicules generally similar to those in 

 Aphrocallistes hocagei, yet some forms exhibited typical differences, namely, "the 

 hexradiate spicules whose pointed arms are sparsely and irregularly covered throughout 

 with smooth spines curved outwards: scopuline spicules whose four rays were quad- 



' Ann. and Mag. Nat. Hist, ser. 4, vol. xii. p. 359. ^ Loc. cit., pp. 449-452, 



