SPONGES.-HALLMAI^ISI. 241 



-digitate sponge,! somewhat resembling Spiyastrella alcyuni- 

 ■oides in habit of growth, which agrees exactly with C. pyra- 

 mida in the form of its spicules. The spicules are, however, 

 slightly larger than in the typical form ; the smooth styli reach 

 a size of 260 x 8 /t, the acanthostylies a size of 160 x 12 ;.(, and 

 the chela? a length of 28 }i. The fibres also are slenderer and 

 much less richl)- provided with spongin.) 



Clathria alata, Dendy.2 From an examination of a slide 

 presented to the Australian Museum by Prof. Dendy, I find 

 that this species differs from the C. pyvamida in the following 

 respects. Fibres are more abundantly developed and much less 

 rich in spongin ; the coring spicules are much less closely 

 packed, giving somewhat of a "whisp-like" appearance to the 

 fibres ; and connecting fibres are relati\ ely fewer in number 

 and much less distinct, so that it requires close inspection to 

 detect that the arrangement of the fibres is not exclusively 

 dendritic. The smooth styli reach a size of about 230 x 4 ft 

 and are usually provided at the basal end with a faint 

 elongated tylosis. The acanthostyles vary in length from 

 about 60 to 140;^ and rarely attain a diameter of 87/. Chelae 

 are extremely abundant ; they differ slightly from those of 

 C. pyramida in this respect that the distal ends or "lobes" of 

 their alae, as seen in profile, project beyond the posterior 

 border of the shaft ; they are also shorter and less robust, 

 never exceeding 22 y. in length. 



Clathria elegantula, Ridley and Dendy. Skeleton "a well- 

 defined reticulation of horny fibre," of which the main fibres 

 alone are cored by sybtylostylote spicules, 200 x 3 /t in size. 

 The microscleres are "palmate isochelae of rather unusual 

 form, with very slender shaft, rather strongly curved and mak- 

 ing an unusually wide angle with the front palm;" they are 

 about 20 ]i long. 



Clathria pinifofmis, Carter. ^ According to description the 

 sponge is erect, lobo-digitate or flabellate, with corrugated 

 surface. Oscula (?). Oxeote modifications of both the smooth 

 coring styli and the echinating acanthostyles occur ; the 

 smooth styli attain a size of 200 x 3 f(. Microscleres are said 

 to be absent, but the presence of chelce has probably been 

 overlooked. 



1 The specimens, which are preserved in a dry state, were inadvertently 

 overlooked in selecting the sponges intended for description, and their 

 discovery came too late to permit of their being figured and described 

 in detail. 



2 Dendy— Proc. Roy. Soc. Vict., viii. (n s.), 1896, p. 34. 



3 Carter— Ann. Mag. Nat. Hist. (5), xvi., p. 354; Dendy— Proc. Roy. Soc. 



Vict.. 1896, p. 34. 



