﻿^34 



•ENDKAVOUR" SCIENTIFIC RESULTS. 



tion with the basal extremity, which in a large pro- 

 portion of cases displays either a rugged surface or 

 some kind or other of tubercular deformity. They 

 vary in length from less than 120 up to 180;; ; and in 

 diameter up to (rarelv) 3 }>. 



Microscleres. — 



Chelae appear to be absent. Toxa, agreeing in shape with 

 those of the preceding forms, but very slender (never quite 

 attaining a diameter of i p), are very scarce. The longest ob- 

 served was i8o)i in length; the shortest (apparently) are 

 between 50 and 60 /( long, and are of extreme tenuity. 



Loc. — Port Phillip, \'ictoria (Austr. Mus. Coll.). 



Clathria arcuophora, ]V]iiteleg<^e. 



(Text figs. 49, 49«). 



1907. Clathria arcuophora, Whitelegge, Austr. Mus. Mem. 

 iv., Pt. 10, 1907, p. 500, pi. xlv., fig. 29. 



Sponge flab ellif arm, thin, stipitate. Surface very 

 closely dotted toith minute pinhole-like {sub-dermal?) 

 pores. Skeleton arrangement semi-axinelloid. In the 

 middle region of the sponge-lamina {occupying about 

 one-fourth to one-third its thickness) is an irregular reti- 

 culation of fairly stout spongin fibres, ivith a discrete 

 spicidar core; and from this mid-region, on either side, 

 stout strands of loosely and someivhat plumoscly arranged 

 spicules, held together by a relatively small or even in- 

 appreciable amount of spongin, run perpendicularly out- 

 wards to the surface in a regularly pinnate fashion. These 

 ''secondary'^ fibres are joined at short intervals by con- 

 nectives of a spictde's length, each consisting of one to 

 several spicides. Echinating acanthostyli moderately 

 abundant. Megascleres.- — {i.) Smooth, curved, sub- 

 conical principal styli, varying in size from 100 x 12 ]i 

 to 620 X 2^ n; {ii.) straight, sub-conical acanthostyles 

 with small spines or merely rugged surface, 60-100 x 8 p.; 

 {Hi.) straight auxiliary sub-tylostyli, often with minute 

 basal spines, 120 to j6o }i in length, and up to 6.5 p in 

 diameter. Microscleres. — (i.) Isochelce palmatce 20-22 p 

 long: {ii.) tricurvate boiv-shaped toxa, 10 to ij^ p in 

 length, and 7ip to 4 p in diameter. 



Five specimens of this species were obtained, which agree 

 in all respects with the original, except that the lamina, 



