192 



'ENDEAVOUK" SCIENTIFIC RESULTS. 



point to point in outline and in area. The thirkness of the 

 iDranches perpendicularly to the plane of branching varies from 

 3 to 6 mm. ; in the transverse direction they are of variable 



breadth, sometimes appearing to 

 a slight extent irregularly mon- 

 iliforni, and almost invariably 

 becoming much expanded prior 

 to bifurcation. The encrusted 

 appearance of portions of the 

 surface of the figured specimen 

 is due to a stoloniferous Alcyon- 

 arian. 



The fibres are of about equal 

 stoutness to those of the pre- 

 ceding variety. Also, the echin- 

 ating acanthostyles are of ap- 

 proximately equal abundance, 

 and are often deeply imbedded in 

 the spongin. In regard to their 

 spicular characters, however, the 

 two varieties are well distin- 

 guished. In the present variety, 

 the megascleres are much slen- 

 derer ; the auxiliary spicules are 

 much longer, and approach more 

 nearly to the principal st}ii in 

 point of stoutness ; both aux- 

 iliary and special derma! spicules 

 are tylostylote or subt} lostylote, 

 and appear to be entirely devoid 

 of the characteristic basal spina- 

 tion of other varieties ; and 

 finally, the acanthostyles are 

 clavate or subclavate, and have 

 smaller and more numerous 

 spines. The greatest dimensions 

 of the spicules are as follows : — 



Mes^asclercs. — 



(i.) Principal styli, 220-240 

 X 7.5-8.2 II. 



(ii.) A c a n t h o styli, 70-S0 

 (rarely 85) x 5-6 ft. 



(iii.) Auxiliary tylostyli, 320- 



365 X b.5-7 )l. 

 (iv.) Dermal tylostyli. 



Fig. 38 — A\ t. var. oeminus. 

 a Principal stylus, b Auxiliary 

 styli. b' Basal extremities of 

 ditto, c Special dermal styli. 

 d Acantbostyli. e Larger chelie. 

 f Smaller contort cbela. g Toxa. 



usually 

 >^ 4-5 H- 



less than i ^o 



