THALASSOMOEA. — ANCORItSTA. 41 



(2) Monact Megasdera. Oxea 1-6 x 0'058 millim., nearly straight, spindle- 

 shaped, sharp-pointed, forming a fibrous skeleton in the interior. The bundles 

 contain 5-12 series of spicules. — (3) Stellate Microscler a. Small, inconspicuous, 

 scattered through the pnlpa ; with slender rays, 0-008 millim. in diameter. — 

 (4) Spindle-shaped Microsdera. Small, numerous, scattered throughout the 

 interior, of an oval shape, 0*01 millim. long, and O'002-l: millim. thick in the 

 centre. — (5) Monact Microsdera of the SJdn. Vertical to the surface and pro- 

 jecting beyond it, slender hair-like rods 0"16 millim. long and O'OOl millim. 

 thick : generally rounded at the ends (strongyla). 



GrEOGKAPHiCAL DiSTEiBUTioisr. — East coast of Australia : Port Molle, 

 Queensland {liamsay). 



Familia ANCORINID^ *. 



Trianina without microsdera. 



Genus ANCORINA. 



A cortex is developed. Megasclera monact and tetract. No 

 root-tufts of spicules. 



Ancorina australis, n. sp. 



Massive sponges, with irregular, small, digitate processes, attached by a small 

 base and measuring 35 millim. in diameter. Surface hairy, shagreen-lilie ; 

 viewed from without, a dark reticulation with meshes 1 millim. wide makes its 

 appearance in it. This network is the expression of the terminations of the 

 tufts of radiating spicule-bundles which are separated in the surface by tissue, 

 in which only few spicules are contained. Colour in spirit light grey. 



The subdermal cavities are small, and have the shape of tangential canals 

 extending between the surface-tufts of radiating spicules ; most of them have a 

 triangular transverse section ; their average width is 0-2 millim. ; here and there 

 they extend laterally to a transverse diameter of 1 millim. The inhalant 

 canals which originate from them are small and much and irregularly brauched. 

 The exhalant canals join to form irregular lacunae in the interior of the sponge, 

 the walls of which are very spiny ; the spines form a perfect filter. The oscula 

 ai'e circular and situated in groove-shaped depressions on the surface of the 

 sponge ; they measure from 1-2 millim. in diameter. 



* The i'amily Aucoriiiida' in this sense is much more restricted than the "'Aneorinidffi'' of 

 J 'osmacr. 



