,Q PORIFERA. I. 



canals vary in size up to ca. 0-5""". As separate oscnla are not seen, we have here probably both the 

 incurrent and the excnrrent systems of canals, so that the larger canals and pores are the excnr- 

 rent ones. 



The skflrfoii. Besides the above mentioned closely packed la\'er of spicules found in the dermal 

 layer, the skeleton consists of spicules spread through the tissue in all directions without any order, 

 or sometimes arranged somewhat like bundles; here and there they may be gathered into larger 

 numbers forming something like fibres; where they are spread in the tissue, they are not close packed, 

 for instance not nearh' so close as in //. colossrn. The membranes lining the canals, have no spicules. 

 Besides the skeleton constructed as above described, elements are found, which certainly bear a pro- 

 minent part as skeleton, the species receiving to a high degree extraneous bodies, chiefly Foraminifera 

 and especiallv sponge-spicules. Thus I have found needles of Desmacidonids, .Suberitids, and of several 

 T'etractinellids, as well as pieces of skeletons of Hexactinellids '); the\- ma)- be present in so great 

 numbers as quite to disguise the real skeleton of the sponge. 



Spiciila are oxea; they are slightly curved or straight, and long tapering; a few o.xea ma\" 

 show a swelling in the middle, and this peculiarit}' seems to be more frequent in some specimens 

 than in others. The spicules are very much varying in length, from o'37""" down to o-o6™"\ the thick- 

 ness varies from o-oo4"'"' in the smallest ones to 0'Oo8™"\ in a few specimens up to o'oio"""; the thick- 

 ness is generalh- proportionate with the length; in the shorter spicules the tapering is comparativeh- 

 shorter than in the longer ones. Whether the short needles are developmental forms of the long 

 cannot be decided with certainty, but it would seem rather probable with regard to some of them, 

 and the very few spicules that were finer than the given measures, belonged also to the short ones; 

 some of the short spicules, however, and especialh- the very shortest ones are scarcely- developmental 

 forms, to judge by the proportion between length and thickness. 



This sponge shows a peculiar tissue of a vesicular structure; it consists of round, more rareh- 

 a little oval cells, lying close together with a comparatively slight intercellular substance. The cells 

 have an average size of ca. O'Oi™'". The\- stain rather slighth' iir fuchsine, and frecpienth- show a 

 little, more strongly stained calotte in one side, where perhaps the nucleus is found. It is no doubt 

 a consequence of this structure of the tissue, that the sponge by drying up contracts very strongh- 

 to an unrecognisable mass, almost as hard as bone. Also the specimens kept in spirit convey, espe- 

 cially on account of tlieir dermal la^er being in many places wrinkled and folded, an impression of 

 being somewhat contracted. 



Locality: Station 78, 60° 37' Lat. N., 27 52' Long. W., depth 799 fathoms, four specimens and 

 some fragments; .station 90, 64' 45' Lat. N., 29° 06' Long. W., depth 568 fathoms, two smaller specimens. 



Note. I have not thought it justifiable with certainty to refer this species to the genus 

 Halichovdria, to which genus it would have to be referred by its spiculation and .skeletal structure. 

 It is no doubt very closeh" allied to Ifnlicliondria iiigrociitis Cart. (Aiiiorphi/ia Carter, Ann. Mag. Nat. 

 Hist. 1886, vSer. V, vol. XVII, 50, 2. — Halicliondria? Dendy, Proceed. Roy. Soc. Vict. 1895, vol. VII, 239) 



') Both the stations, 78 and 90, on which the species was taken, gave exceedingly rich earnings of sponges, especially 

 many Tetractinellids, among which accordingly the species must have grown. 



