SPOSTGIIBA. 



449 



slio-w to greater advantage, that the stag's-hom-like branches anas- 

 tomose and inosculate very freely with each other, forming a number 

 of deep angular cells, open above and below, and more or less at the 

 sides also, owing to the fenestras left between the branches. The 

 Australian specimens mostly exceed Bowerbank's type in their 

 dimensions : the largest measures 110 miUim. (if inches) by 115 

 millim. (4|- inches) in extreme height and breadth respectively ; it is 

 formed of three main lobes which arise from a common base and 

 unite towards the summit of the sponge. 



The measurements of the spicules are given, as Bowerbank hs» 

 not figured them : — 



Sab. Thursday Island, 4—5 fms. ^ Prince of Wales Channel, 

 5-7 fms. ; Percy Island and Fitzroy Island, Queensland, 7-11 fms. ; 

 bottom — combinations of sand, mud, or shells. 



Distribution. Straits of Malacca, Gaspar Strait (BowerbanJc). 



The presence of spined echinating spicules removes the species 

 from Amphilectus, where it had been placed by Vosmaer, who had 

 only an imperfect description to guide him. It must be referred to 

 Clathria as emended by him j and it is interesting to find here a 

 variability in the development of the horny fibre in different speci- 

 mens which is similar to what he has described (I. c. p. 150) in 

 C. eoralloides. 



The second Queensland specimen (" B "), firom Percy Island, 

 differs decidedly from the rest in the greater slenderness of its 

 skeleton-spicules ; it is, however, a j'oung specimen, and the dif- 

 ferences may be due to this circumstance. 



RHAPHIDOPHLUS. 



Thiers, Die Espersch. Spong. pp. 19, 31. 



This genus differs from Olaihria only by its spicular crust, and 

 from EcMnonema, Carter, only by the absence of tricurvate spi- 

 cules. 



2a 



