656 REVISION OF THE AXINELLIDiE, iii., 



scleres: styli and (or) oxea, usually of two or three kinds. 

 Megascleres of a single kind, in the form of centrangulate spined 

 microxea. 



Type-species, H. coralloides Higgin. 



The genus Iliyfjinsia is here defined so as to include also 

 Ridley and Dendy's Deudropsis, with its two species D. bidenti 

 /era and D. mixta, — the latter recently added to the genus by 

 Hentscliel(15). The I'eason for this is not that the differences 

 between liigyinsia coralloides and Dendropsis hidentifera, the 

 respective type-species, are insufficient to warrant their generic 

 separation, but that intermediate species exist between them, 

 forming with them (in so far as skeletal characters are concerned) 

 a gradational series incapable of subdivision into two groups 

 except in an arbitrary way. This fact will be clear from the 

 following synopsis of the chief distinguishing characters of the 

 several species. 



Dendroj)sis bidentifera Ridley & Dendy(33). Uichotomously 

 ramose, with slightly compressed branches disposed in one plane. 

 Skeleton consisting (i.)of a dense axial core of interlacing, com- 

 paratively short styli; (ii.) of bundles of much longer styli (up to 

 1100 by 44/x in size) radiating from the axis to the surface, 

 beyond which the apices of many of them project; (iii.) of sheaves 

 of slender oxeote spicules surrounding (ii.), which are peculiar in 

 being double-pointed at one extremity, and also often project 

 beyond the surface; and (iv.) of long slender styli (up to 1750 by 

 20/i. in size), occasionally passing into strongyla. 



Dendropsis mixta Hentschel(15). Thick, encrusting ; with 

 short digitiform processes. Skeleton consisting (i.) interiorly of 

 irregularly arranged stout oxea (up to 750 by 31/x in size); (ii.) of 

 long slender styli (up to 2240 by SI/a in size) projecting beyond 

 the surface; (iii.) of bundles of slender oxea (up to 1175 by 5/x in 

 size), forming dermal tufts around (ii.) as in the genus Jiasjjailia, 

 and also passing inwards towards the interior. 



Higginsia papillosa Thiele(42). Massive, ovoidal; with papil- 

 lose surface. Skeleton consisting (i.) of stout fibres, formed of 

 styli, radiating to the surface and ending in the surface-papillie, 



