1881.] THE SURVEY OF H.M.S. 'ALERT.' 109 



The great regularity of its skeleton, and its distinction into two kinds 

 of fibres differentiates it from Dendrospongia, Hyatt, as well as from 

 the other known species of its genus. The characters of the axial 

 fibre-substance distinguish it from Ferongia, Bowerbank. 



Order Psammonemata, Carter. 



HinciNiA HispiDA, Lamarck (sp.). 



Spongia hispida, Lamarck, Ann. Mus. Hist. Nat. xx. p. 452. 



External Characters '. The single (spirit) specimen agrees fairly 

 well with the characters assigned to this species by Lamarck (/. c), 

 and with the specimen of the species already in the British Museum. 

 It being, however, evidently young, the branching character is no 

 more than indicated by the extension outwards of a rounded lobe 

 from each side ; and as it is a well-preserved spirit specimen, the 

 small foramina of Lamarck's description and of the dried specimen are 

 wanting. It is sessile by a broad base, and suboval in outline, the 

 long axis extending from side to side. Surface uneven, rendered 

 coarsely hispid by the projecting ends of the primary skeleton-fibres, 

 arranged at intervals of from -5 to IvS millim. (to 2 in the 

 dried state). Colour in spirit dark brown, slightly rufous; of dry 

 skeleton, pale yellow-brown. 



Vents few, round ; diameter in spirit TS millim., in dried specimen 

 2 to 3'.5 millims. Pores 1 



Skeleton. Consists of a set of stout primary, generally sand-cored, 

 fibres running outwards from the interior, each terminating at right 

 angles to the surface in one of the surface-papillae. These are con- 

 nected by a secondary set, consisting of an irregular network of 

 much finer, uncored fibres, meeting the primary fibres at acute 

 angles, and forming by their l)ranching and anastomosis irregularly 

 diamond-shaped meshes. Surface network formed by secondary 

 fibres connected with the interior secondary-fibre network, and 

 laterally with the apices of the primary fibres. Primary fibres 

 cored by coarse foreign bodies, which are enveloped by pale-yellow 

 horny matter, but which generally occupy all the fibre except a slight 

 external film, and cause it to bulge largely at the sides ; diameter 

 from •0507 to -235 millim. in the spirit, from -038 to '0834 in the dry 

 specimen. It should be noted with regard to this discrepancy that 

 the foreign bodies in the latter are much smaller than in the former, 

 and being many of them sponge-spicules, which protruded from the 

 fibre, were not included entirely in the estimate of the diameter as 

 given here. There is considerable irregularity as to whether the 

 fibre is cored throughout or not in this specimen, which may be due 

 to the reason suggested by Hyatt ^ for a similar fact observed in 

 Carteriospongia otahitira, viz. the relatively smaller amount of 

 accessible material for the core in the one case. Secondary fibres 

 obscurely striated, the external lamina) denser than the internal ones, 



' All the characters are taken from the spirit specimen, deviations in the dry 

 one being noticed. 



^ Mem. Bost. Soc. ii. pt. ir. p. 541. 



