BY E. P. KALLMANN. 527 



occur in dragraata, as well as scattered singly, but the shorter 

 dragmata are rare. 



(iii.)The trichites, both forming the dragmata and scattered 

 singly, are exceedingly slender microxea, varying in length from 

 20 to 4;V. 



SiGMAXINELLA DENDROIDES Whitelegge. 



(Phxxxiv., fig.2.) 



1907. Sigmaxinella dendroides Whitelegge(60), p. 51 3, PI. xlvi., 

 fig.42. 



Diagnosis. — Ramose, erect, stipitate; Avith cylindrical, tapered, 

 dichotomously dividing, slender branches of moderate length. 

 Surface even. Oscula presumably either very small or very 

 shallow, at any rate not apparent in the skeletonised specimen. 

 Dermal features unknown. Skeleton consisting (i.) of a con- 

 densed axial reticulation, the fibres forming which are moder- 

 ately rich in spongin, and (ii.) of fibres radiating therefi'om which 

 are poor in spongin, are united only sparingly by (entirely 

 sponginous) transverse fibres and by single spicules, and run 

 (with occasional branching) in nearl}' parallel courses to the 

 surface, becoming multispicular and somewhat plumose on near- 

 ing it, and terminating each in a subpenicillate tuft. The 

 spicules of the radial fibres are of greater average length than 

 those of the axial x'eticulation. Megascleres : subcylindrical 

 styli, usually tapering gradually to a sharp or slightly rounded 

 point at the apex, and usually slightly curved, sometimes bent; 

 frequently tending to become abruptly blunt-pointed at the base; 

 occasionally passing into strongyla, very rarely into oxea; 300 

 to 640/x long by 10 to 26/x in diameter. Microscleres : slender 

 sigmata of two sizes, respectively 20 to 40/i. in maximal length; 

 and scarce trichites (microxea), 25 to 35/>i long, scattered singly. 



Loc. South of Port Hacking, N.S.W. ("Thetis"). 



External features, — The only known specimen— a figure of 

 which has been furnished by Whitelegge — is a stipitate arbor- 

 escent sponge, 180mm. in total height, with moderately elongated, 

 cylindrical, distally tapered branches, 4 to 6 mm. in diameter, 

 rising erectly from an equally slender stem, and occasionally 



