synopsis of the Ausfrdllaii Calcarea Heterocwla. 77 



skeleton of the chamber layer is composed of the apical rays 

 of subdermal and subgastral quadriradiates. There is a 

 root-tuft of oxea and anchoring quadriradiates. 



The only known species of this remarkable genus is 

 Hiieckcl's Sijculmis suYKipla,^' from Bahia. 



Genus XIX. — LcuciUa (Ha^ckel, emend.) 



Diagnosis. — Flagellated chambers spherical or sac-shaped, 

 never truly radial. 



(For examples see Part o of the present paper.) 



Genus XX. — Faraleucilla, nov. gen. 



Diagnosis. — Chambers spherical or sac-shaped (?). Be- 

 neath the dermal cortex a series of subdermal cavities 

 supported by an outer and inner layer of quadriradiates 

 whose apical xixya cross each other in opposite directions. 

 Beneath these comes the chamber layer, whose skeleton 

 consists ot irregularly arranged quadriradiates. Large, 

 longitudinally arranged oxea occur between the triradiates 

 of the dermal cortex. 



(For species see Part 3 of the present papei'.) 



o. Synopsis of the Australian Species of Calcarea 

 Heteroccela. 



1. Leucascus simplex, n. sp. 



Sponge usually more or less flattened, cushion-shaped, 

 spreading, with convex upper surface ; sometimes becoming 

 almost globular. Oscula irregularly scattered on the upper 

 surface, one or several, varying in size, naked. Surface 

 smooth. The largest specimen is a rather thin, ovoid,^ 

 flattened ci'ust, which, from its shape, appears to have 

 grown on a crab's back ; it is about 3o mm. long, 20 mm. 

 broad, and only about 2 mm. thick in most parts ; the other 

 specimens, though smaller, are much thicker, one being 

 nearly spherical. The surface is covered by a thin, pore- 

 bearing dermal membrane. 



* Die Kallvschwamme, VoL 11, p, 288. 



