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 0"3 mm. in length. 



Subgastric triradiate S2ncules : 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, vaiying 

 from 0-02 to 0*05 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 

 0-8 mm. Triradiate spicides 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 0-025 mm. 



Dermal triradiate spicides : 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. SYLLEIBir>JE. V^on Lendenfeld. 



Heterocoela with a complicated exhalent canal system, connect- 

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

 cavity. The Sylleibidse are transition-forms between Syconidae 

 and Leuconidjfi. They can be considered as Syconida3 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. 



