PORIFERA. I. 



Spicula are slightl\ curved or, rareh', straight oxea, with very evenh-, but not exactly long 

 tapering- ends. The length varies from 0'33 — 0'43""'', but appears to be most frequently towards 0-4""". 

 The thickness is quite constant 0-013— o-oisj'"™. Shorter and finer spicules are seen quite singh. 



Locality: Station 81, 61^ 44' Lat. N., 27" 00' Long. W., depth 485 fathoms, one specimen. 



On account of its distinct primary fibres that support a dermal membrane without spicules, 

 this species like the preceding one belongs to those species of Haliclioiidria approaching the Reniera. 



8. H. colossea n. .sp. 

 PI. Ill, Figs. 1—2, PI. X, Figs. 3—7. 

 Of ail irreg^nlar ca/rc/ilar, somewhat compressed form. The surface of the outside of the sponge 

 mostly smooth, but the upper surface and that of the calicular cavity shaggy from, projecting spicules. 

 The skin provided iijith closely packed spicules of the smaller form, running parallel to the surface; 

 where the skin is shaggy, this layer is pierced by projecting large spicules. Oscula arc found in the 

 calicular cavity. The skeleton consists of closely packed needles., and is without fibres ; consequejttly 

 the consistency is firm and hard. Spicula oxea varying in length from n-r^""" to about 2""" ; they 

 divide into tivo, not sharply distinct, groups of sizes, of luhich the smaller are found in the skin and 

 on the membranes of the canals. 



The onl\- specimen in hand of this species is very large and of an irregular, somewhat com- 

 pressed calicular form. To be sure it cannot be decided with certainty, b\- which part the sponge has 

 been attached; but probabh" the calicular cavity has been turned upward, and the sponge has been 

 attached \i\ the opposite part. The specimen has a height of 30™, a length of 50™, and a breadth of 

 25^'". The cavitv has a depth of about 14™ and a breadth of about 8"", and, as shown b\' the picture 

 pi. Ill, fig. I, is Iving somewhat in one side of the sponge. The surface has irregular, flat depressions 

 and folds, but on the outside of the sponge it is otherwise mostly rather smooth; on the upper side 

 and in the calicular hollow, on the other hand, it is provided with projecting spicules, so that here it 

 appears shagg^■. The colour (in spirit) is gray-brown. On account of the needles that are closeh- 

 packed throughout the sponge, the consistency is firm and hard. The dermal membrane is only with 

 difficult\- to be separated from the tissue below; it is provided with closelying spicules parallel to the 

 surface. Oscula are found in the calicular cavit)-; they are rather large and ver\- irregular, the larger 

 part of the walls and bottom of the cavity being occupied h\ oscula and \>\ the folds between 

 them, and thev pass so gradually into the wide canals, that no distinct boundar>- is to be found be- 

 tween osculum and canal; strictly speaking the cavity is a large groove, divided into smaller ones 

 passing at last into the system of canals. Also outside of the calicular cavity smaller depressions 

 with oscula ma\- be found on the upper surface. In spite of an examination of several stained pieces 

 of the dermal membrane, no pores have been found; on account of the dense spiculation of the mem- 

 brane they are perhaps onh- found in particular places. 



The skeleton consists of an exceedingly dense tissue of needles King without any order among 

 each other in every direction. The dermal membrane is provided with a ver\- dense spiculation; the 

 needles lying side by side in every direction parallel to the surface, but in such a way, that they are 

 situated in groups in which the .spicules are parallel to each other ( pi. X, fig. 4 ). These spicules are all 



4' 



