138 THE VOYAGE OF H.M.S. CHALLENGEE. 



withuut lieacls, flexed outwards and arranged en Jieur-de-lis ; pappilbrm, or sometimes 

 many-rayed with rays straight and capitate. Anchoring spicules all smooth, stout and 

 terminating respectively in heads oifouv equally stout recurved spines or hooks." 



In 1875 Carter happened to discover among the treasures of the British Museum "a 

 glass jar containing two small specimens of the veritable RosseUa antarctica dredged up 

 by Sir J. Eoss in 300 fathoms 74^° S. lat.," longitude not given. 



"The general form of this sessile or fixed sponge was sack-like (compressed) with the 

 upper end truncated and open and the lower one conical and closed. External surface 

 uniformly cribellate and monticular, covered by a thin layer of spicular lattice-work and 

 surrounded by three forms of projecting spicules : — viz., (1) stout linear smooth nearly 

 straight fusiform acerate spicules, finely pointed at each end, constituting an erect beard 

 round the aperture; (2) anchoring spicules which increase in number, size, and length 

 towards the lower or conical end ; (3) crucially headed or veil spicules projecting chiefly 

 from the monticules over every part of the external surface but the aperture, consisting 

 of a shaft whose pointed or inner end is fixed in the sarcode of the body, and whose free 

 or outer one is terminated by four long arms spread out horizontally so as to intercross 

 with those of its neighbours, and thus form a general veil-like covering separated from 

 the body by the length of the shafts between the body and their heads respectively ; 

 shaft smooth or only microtuberculate over the imbedded end, arms more or less flexuous, 

 fine-pointed, parting from the head of the shaft at difi"erent angles, covered almost 

 throughout with minute spicules closely approximated, amongst which here and there is- 

 a much larger sjjine curved and inclined outwards or from the head of the shaft." 



Among the seven other forms of spicules which Carter has described from the body 

 of the sponge the following are especially noteworthy : — 



" (1) Very minute sexradiate rosettes with numerous straight capitate rays, and (2) 

 sexradiate rosettes with thick sparsely spined arms, whose inflated ends supjsort four or 

 more indistinctly capitate rays ; rays raicrospined, thick at first, then becoming finely 

 attenuated and terminating in a hardly perceptible capitate inflation ; rays at first straight 

 and parallel like the prongs of a dinner-fork, becoming more or less divergent towards- 

 their extremities." 



In his systematic review published in the year 1875,^ Carter placed the genns Bossella 

 along with Cratcromorpha in a grouji called the Eosettifera within his family of the 

 Sarcohexactinellidse. 



The characteristics which Marshall " in 1876 assigned to the genus RosseUa ran thus: 

 — " Monozoic, root-tufts springing from papilla-like hillocks on the j^arietes, dermal 

 skeleton composed of five-rayed spicules. In RosseUa antarctica a peristomal spicular 

 wreath (whether present in the other species is doubtful)." 



C/iaracter of the Genus. — Thick-walled, ovoid or cask-shaped goblets, with a superior, 



' Ann. and Mag. Nat. Hist., ser. 4, vol. xvi. p. 199. ^ Zeitschr.f. wiss. Zool., Bil. xvii. p. 127. 



