6P0NGIIDA. 447 



specimens recall strongly, from their habit and size, the figure of this 

 species given by Esper ( Pflanzenth. ii. pi. xlv.), with which Vosmaer's 

 specimen was at first erroneously identified. 



The following are the leading points in the external characters: — 

 The specimens are abundantly 1) ranched, the stems and branches 

 are either roughly cylindrical below (usually flattened at the 

 ends), greatest diameter about 9 miliim. in the cylindrical, 12 to 

 14 miliim. in the compressed parts. Anastomosis frequent, pro- 

 duced by lateral adhesion of branches, sometimes forming broad 

 expansions of sponge-substance. Surface entirely broken up by a 

 system of anastomosing, more or less sharp, usually jagged ridges, 

 2 to 3 miliim. high, often drawn up into prominent detached points. 

 Texture in dry state subelastic, firm, harsh to touch. Maximum 

 extent of largest specimen 180 miliim. (7-\ inches). Skeleton : indi- 

 cations of horny matter in fibres slight and infrequent ; fibres usually 

 wholly composed of the smooth skelcton-spicule, about 8 spicules 

 broad, and sparingly echinatcd by the spined cylindrical form. 

 Spicules: I cannot find any spinulates, those which Vosmaer de- 

 scribes are perhaps young forms of the smooth acuate ; nor do I find 

 the smooth cylindrical which he places within brackets. 



( 1 ) The skeleton smooth acuate, has a well-rounded head and tapers 

 gradually to a sharp point ; size "25 by *0127to -28 by -0095 miliim. 



(2) Smooth acuate, occasionally echinating, measures -22 by 

 •l 1 127 miliim. 



(3) The spined echinating cylindrical tapers to the smaller blunt 

 end ; the spines project directly outwards from the shaft and are 

 about equally distributed over the whole spicules ; size *076 by *0063 

 miliim. 



(4) Equianchorate, -019 miliim. long. 

 Colour, in dry state, grey or very pale brown. 



Vosmaer's description being short and merely preliminary, 1 have 

 thought it well to give the chief details (although I hope he will 

 himself figure or further describe his species) to obviate any future 

 uncertainty as to the identity of the present form. 



Hub. Thursday Island, Prince of Wales Channel, Torres Straits, 

 3-7 fms. ; common. 



Distribution. Moluccas ( Vosmaer). 



Vosmaer states that his specimen is unbranched. 



Clathria reinwardti, Vosmaer, var. palmata. 



It is not surprising to find Clathria exhibiting individual varia- 

 tion in its external form of a character similar to that which occurs in 

 the nearly allied genus Echiaonema. As in that genus the same 

 species may be either cylindrical or semipalmate, so here. In this 

 collection occur two specimens from one locality, which, though dif- 

 fering greatly in form from each other, have the same colour, a 

 surface of similar character, and agree closely in spiculation. 



The one arises from a stout, laterally compressed, short pedicle, 

 and expands rapidly into a fan-shaped but rather thick expansion- 



