﻿170 "ENDEAVOUR" SCIENTIFIC RESULTS. 



sponge; at the surface they are penicilhitely spread out, form- 

 ing sub-dermal brushes with the points of the spicules imping- 

 ing on, but not piercing, the dermal membrane. The principal 

 columns appear never to quite reach the surface but to be 

 invariably capped with a column or a brush of oxea. The 

 interstitial megascleres are almost exclusivelv acanthostvles : in 

 the upper part of the sponge they are sometimes \er\ numer- 

 ous, and form a conspicuous feature of the skeleton ; but this 

 is not a constant feature, and generally speaking, scattered 

 spicules are of no great abundance. The dermal skeleton 

 consists solely of irregularly and fairh- closelv scattered ac- 

 cessory acanthostyles. 



Megascleres. — 



(i.) The oxea vary in length from 130 to 170;* and are thus 

 shorter than in any other of the known varieties. 

 They are slender spicules, rarely exceeding 4.5 ;< and 

 never more than 5.5 ;( in diameter. 



(ii.) The principal acanthostyles attain a niaxiiiiuiii size of 

 145 X lOtl. 



(iii.) The dermal acanthostyles vary in length from about 

 60 to 80 /( ; the stoutest are less than 6 ji in diameter. 



MicroscJeres. — 



The chela; are of a single kind, similar to those of the 

 variety levis, and 12-16 j^t long. 



Loc. — Port Jackson (Austr. iMus. Coll.). 



Crella in'crust.ws. Carter, v.\r. rubra, LencleufeJd. 



1888. Clathrissa pumila var. rubra, Lendenfeld, Cat. Sponges 

 Austr. Mus., 18SS, p. 2i<). 



Very small, encrusting or cake or dome-shaped sponges 

 with smooth or papillated surface. Main skeleton con- 

 sisting of hranching, ascending, occasionally anastomos- 

 ing, fairly densely echinated fibres often with a distinct 

 core of oxea, but usually ivith acanthostyles in addition 

 and sometimes containing acanthostyles alow. There 

 are no descending columns of smooth oxea as in the pre- 

 ceding variety. The dernml skeleton consists of scat- 

 tered accessory acanthostyles. Megascleres, nmximum 

 sizes: — {i.) Oxea, 200 x 5 pi; (ii.) principal acanthostyles, 

 160 X 8 Ji ; {Hi.) dermal acanthostyles. So x 5 \i. Iso- 

 chelcc arcuatce, 12 to 16 f( long. 



The original description of the external features of this 

 sponge was as follows: — "Massive or incrusting sponges with 

 Rmall conuli about i mm. high which are \'er\- close together. 



