1116 A MONOGRAPH OF THE AUSTRALIAN SPONGES, 



Suhgastric triradiaie spicules sagittal. All rays sharp pointed 

 and of the same diameter, the i)roportion between their length 

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

 exceeding, however, 0-6 mm. in basal, and 0-42 mm. in lateral 

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



Quadriradiate spicules of the imrenchyma and dermis : All rays 

 of the same diametei-, rarely exceeding 0-05 mm. ; facial rays 

 usually of the same length, varying from 0*4 (rarely shortei') to 

 6 mm.; basal ray sti'aight, tapering from an approximately 

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

 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 aceraie S2ncules straight, fine, lineai", sharp pointed, 

 surface smooth, length not exceeding 0'4mm., with a diameter of 

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



Locality: Station 36, April 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^. 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 {\], with spherical chambers with the exception of the 

 Teichonidse. 



17. GENUS. LEUCETTA. Von Lendenfeld, 



Leuconidfe with triradiate spicules exclusively. This Genus is 

 nearly identical with Haeckel's (2) Leucetta. 



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

 Seite 113. 



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



