1110 A MONOGRAPH OF THE AUSTRALIAN SPONGES, 



inwards, each forming with basal ray an angle of about 110° ; 

 some of them are provided with embryonic apical rays, reaching 

 occasionally 0-2 to - 3 mm. in length. 



Subgastric triradiate spicules : Sagittal ; lateral rays either 

 lying in the same plane or forming with one another an angle 

 varying from 180° to 140° ; all rays of the same diameter, varying 

 from 0-02 to O05 mm. ; basal ray straight tapering from the base 

 to a sharp point reaching 0'8 mm. in length; lateral rays curved, 

 often undulating usually half as long as basal ray, often of the 

 same length, occasionally even longer, not exceeding however 

 0'8mm. Triradiate spicules of the Parenchyma either quite 

 regular, or showing a slight tendency to sagittal differentiation ; 

 rays sharply pointed maximum size about 1 mm., diameter varying 

 from 0-1 to 025 mm. 



Dermal triradiate spicules : Regular, more slender than the 

 triradiate ones just described ; rays either tapering from the base 

 to a sharp point or of cylindrical form ; average size of the rays 

 0-3 mm. in length by 002 mm. in diameter. 



Color : Pale yellowish. 



Locality: Torres Straits, Australia, September 7, 1874; depth 

 3 to 11 fathoms. Challenger. 



5. FAMILY. SYLLEIBII^E. Von Lendenfeld. 



Heterocoela with a complicated exhalent canal system, connect- 

 ing the sack-shaped, cylindrical ciliated chambers with the gastral 

 cavity. The Sylleibidte are transition-forms between Syconidaa 

 and Leuconidse. They can be considered as Sj'conidge with an 

 exhalent canal net, or as Leuconidse with cylindrical sack-shaped 

 ciliated chambers. I establish this family for Leucetta vera and 

 the Genus Lucilla of Polejaeff and devide it into two Subfamilies, 

 which represent different modes of development of the Canal system 

 and which I name after the two greatest authorities on Calci- 

 spongire among the younger zoologists, Vosmaer and Polejaeff. 



