132 ZOOLOGICAL COLLECTIONS MADE DURING [Jan. 4, 



With regard to the amount of distmctaess between the new species 

 and their nearest allies, the remarks or tables given under each sponge 

 should be consulted. It should be remembered, in estimating the 

 relations of this fauna, that comparatively few species have been in- 

 telligibly described from any seas but the Atlantic and Mediterranean ; 

 but even allowing for that, the fact that in but one case the nearest 

 ally is to be found outside those two areas speaks strongly for the 

 Atlantic fades of the Magellan and S.AV. Chilian fauna. 



Subclass CALCAREA. 



The technical terms here used are those employed by Hiickelin his 

 ' Kalkschwamme,' and with the meanings there applied to them. 



The collection, it will be seen, contains the British form Clathrina 

 coriacea (hitherto known only from arctic and north temperate seas) 

 and the Australian species C. poterium as its sole representatives of 

 a INIagellan fauna. Considering the number of dredgings in shallow 

 waters which have been taken here, this result may be considered as 

 probably showing the extreme poverty of this region in Calcisponges. 

 A striking contrast to this is furnished by the dredgings at the 

 Victoria Bank, a shoal to the north-east of Rio de Janeiro, which 

 was not visited by the ' Challenger,' and from which no Sponges 

 have hitherto been described. Of the four (or possibly five) species 

 which come from this locaUty, three are new, and a fourth has been 

 assigned with considerable doubt to one of the species obtained. 

 The well-known littoral habits of the Calcarea are thus brought 

 forcibly to mind ; for had they been fitted to live in deeper waters, it is 

 almost inconceivable that more of them would not have spread from 

 the mainland, whose fauna is already somewhat known. 



Clathrina coriacea, Johnston. 



(^Clathrina, Gray, P. Z. S. 1867, p. 557; Ascetta, Hackel, Kalk- 

 schwamme, ii. p. 14.) 



Spongia coriacea, Montagu?, Weru. Mem. ii. p. 116. 



Grantia coriacea, Johnston, Brit. Spong. p. 183, pi. xxi. fig. 9. 



This species occurs on a hw species of dead lietepora, forming 

 either (a) a minute tube {Auloplegma form of Hiickel) running over 

 the surface, expanding at intervals into a bulbiform dilatation, and 

 varying in diameter from -18 to -426 millim., or (i) apparently a 

 thin-walled sac of not less than 2"5 millims. extreme diameter. The 

 sarcode is coloured reddish brown by an unevenly distributed pig- 

 ment. The spicules agree with the common type figured by Hackel 

 in the 'Kalkschwiimme,' pi. v. fig. 2, differing slightly from it 

 in being sharply though abruptly pointed, and in being slightly 

 inequiradiate ; they measure: — in (a), basal ray -1267 to -14 

 milhm., laterals -095 to -114 miUim. long, diameter -00844 to -0095; 

 in (5), basal ray -114 to •2027, laterals 'WA long, diameter -00844 

 to -0095 millim. 



These measurements agree closely with those of the spicules of 

 Johnston's specimens of Grantia coriacea. The distribution, already 



