1116 A MONOGRAPH OF THE AUSTRALIAN SPONGES, 



Subgastric triradiate spicules sagittal. All rays sharp pointed 

 and of the same diameter, the proportion between their length 

 and thickness varying from 12*1 to 20 - l ; length inconstant, not 

 exceeding, however, 0-6 mm. in basal, and 042 mm. in lateral 

 rays ; some are provided with a nidimentary fourth apical ray. 



Quadriradiate spicules of the parenchyma and dermis : All rays 

 of the same diameter, rarely exceeding 0'05 mm. ; facial rays 

 usually of the same length, varying from 0*4 (l^arely shorter) to 

 6 mm.; basal ray straight, tapering from an approximately 

 sharp point, forming with each of the lateral rays an angle of 105 u 

 to 110° ; lateral rays either straight or slightly curved inwards, 

 sharp pointed ; apical ray straight, tapering from the base to a 

 sharp point, never projecting from the inner surface, length 

 varying from 0"4 to 1*2 mm. 



Dermal acerate s]?icules straight, fine, linear, sharp pointed, 

 surtace smooth, length not exceeding 04 mm., with a diameter of 

 0-0025 mm. ; not numerous, projecting from the outer surface. 



Locality: Station 36, Api'il 23, 1873; off Bermudas; depth, 

 32 fathoms. Station 209, January 22, 1875 ; Lat. 10° 10' N., 

 Long. 123° 55' E. Philippine Islands ; depths, 95 to 100 fathoms 

 Challenger. Torres Straits, Von Lendenfeld. Macleay-Museum. 



6. FAMILY. LEUCONID^E. Von Lendenfeld. 



Heterocoelia with ramified inhalent and exhalent canals with 

 spherical ciliated chambers. The outer surface is not differentiated 

 into two different parts. This family comprises the Leucones of 

 Haeckel (1), with spherical chambers with the exception of the 

 Teichonidse. 



17. GENUS. LEUCETTA. Von Lendenfeld, 



Leuconidae with triradiate spicules exclusively. This Genus is 

 nearly identical with Haeckel's (2) Leucetta. 



( 1 . ) E. Haeckel. Die Kalkschwamme. Eine Monographic. Band II. , 

 Seite 113. 

 (2.) E. Haeckel. L.c. Band II., Seite 116. 



