BY E. F. HALLMANN. 275 



ceptionally in the case of the sliorter rayed, one to several of the 

 rays are forked, or are once or (seldom) a few times branched, 

 or, on the other hand, are truncated and rounded off at the 

 extremity. 



The tylasters, which form a dense layer in the superficial part 

 of the cortex and are scattered sparsely through the choanosome, 

 are at most 19 /x in diameter, and have short stout rays, about 

 equal in length to the diameter of the centrum, with slightly 

 expanded extremities tipped with numerous minute spines. 



The oxyasters occur abundantly in all parts of the choanosome, 

 but are absent from the cortex. They attain to 50 or 55 /x in 

 diameter, and have only a very slightly developed centrum and 

 from 6 to 8 slender, usually blunt-pointed rays, generally pro- 

 vided with a few minute spines or tubercles, especially towards 

 their extremities. 



Many large spherical embryos occur throughout the sponge, 

 some of which are over 2*5 mm. in diameter. These have radially 

 arranged stylote megascleres and, as microscleres, a very thin 

 superficial layer of tylasters similar to those of the adult, and 

 exceedingly minute developmental spherasters scattered sparsely 

 in the cortex. 



Lendenfeld records the species from Port Molle (Queensland), 

 Port Jackson, and New Zealand. The sj)ecimens described by 

 me are labelled as coming from Port Jackson.* 



If this species is to be placed in the genus Donatia^ as at 

 present seems necessary, then the latter can no longer be defined 

 as being " without highly specialised pore-bearing grooves." 



The sponge described by Hentschel(l9) from Shark's Bay 

 (Western Australia) as Donatia Jissurata var. extensa, is un- 

 doubtedly a distinct species from the above. 



Tethya inflata. 



According to description, this species has a smooth {i.e., non- 

 tessellated) surface with thread-shaped appendages, cylindrical 



♦The Federal trawling-steainer "Endeavour" has now obtained 

 another specimen from Storm Bay, Tasmania. 



