494 " THETIS " SCIENTIFIC RESULTS. 



trabeculae usually have their edges directed outwards, they vary 

 from 1 to 3 mm. in thickness, and the spaces between are on an 

 average about 5 mm. or less in diameter. 



The surface is hispid and minutely porous ; a few oscula-like 

 openings about 5 mm. wide ai"e present on some of the elevated 

 processes. 



Texture both dry and in spirits resilient and rather tough ; 

 colour from greyish-yellow to dark brown. 



The skeleton consists of stout horny fibres arranged in 

 plumose columns ; they are about O'l mm. in diameter and the 

 same distance apart ; the lateral branches given off from the main 

 fibres are gracefull}'^ curved and terminate at the surface in tufts 

 of spicules. 



Megascleres : — (1) Slightly curved styli or subtylostyli ; the 

 base is provided with numerous spines ; the shaft also carries a 

 series which are somewhat variable in size aud number ; they are 

 generally reflexed and are continued to within one or two 

 diameters of the acute apex. These spicules are extremely 

 abundant, and both echinate and invest the whole of the fibres ; 

 size 0-15 to 0-2 by 0*015 mm. 



(2) Stout, curved, basally spined styli; the shaft is smooth, 

 and gradually tapers to a long acute point. These spicules are 

 sparingly distributed in the tibres and are here and there echinat- 

 ing and form slightly divergent tufts of four or five spicules at 

 the ends of the fibres ; the tufts have numerous spiny styli, 

 enveloping the basal area and others, which are either parallel 

 or echinating ; size 0-35 to 0-45 by 0-02.5 to 0-03 mm. 



(3) Slender, straight, smooth styli, chiefly dermal; they form 

 radiating tufts, and also a thin layer in which the spicules are 

 disposed at right angles to the larger projecting spicules at the 

 ends of the fibres ; size 0-15 to 023 by 0-0045 mm. 



Microscleres : — (1) Bow shaped toxa, rather scarce; size 0"06 

 to 0"1 mm. (2) Small isochelae ; size 0*009 mm. 



C L A T H R I A, Schmidt. 



CLATHRIA LENDENFELDI, Bidle^ and Bendy. 



ClatJiria lendenfeldi, Ridley and Dendy, Chall. Rep., Zool., xx., 

 1887, p. 148, pi. xxviii., fig. 5, pi. xxix., fig. 6, pi. xlvii., 

 fig. 5. 



Stations 41, 48. 



There are two examples of this well-marked species in the 

 collection. The principal specific features are the hispid surface, 

 the lateral branches — which are usually short and are given off 

 at nearly right angles — and the stout, very spiny, echinating 

 spicules. 



