﻿SPONGES— KALLMANN. 2 :; c 



individuals may sometimes be left only partially included 

 •within the completed fibre. (iii.) Owing to the continued 

 growth in stoutness of a fibre, spicules originally lying ex- 

 ternally, but in close proximity to it, might secondarily come 

 to be surrounded at their basal extremity by the fibre-spongin. 

 (iv.) In the superficial regions of the sponge, spicules which 

 appear as if echinating, are often nothing more than the 

 axial spicules of incipient connecting fibres ; this occurs most 

 frequently when the connecting fibres are unispicular. (v.) It 

 sometimes happens that the development of a connecting fibre 

 ■ — say, an unispicular fibre— proves abortive, the fibre then 

 appearing as a process from its supporting main fibre; in such 

 a ca.se, if the process were very short, its axial spicule would 

 .appear to echinate the main fibre. 



In the species of Ophlitaspongia described herein, the echi- 

 nating spicules appear to arise in one or other of the ways 

 indicated. 



Dendyi has remarked that his Siphonochalina bispiculata 

 resembles an Ophlitaspongia save in the fact that the spicules 

 are oxea ; perhaps this species should be placed in the genus 

 Diplodemia, Bowerbank. 



Ophlit.aspongia coxfragosa, sp. nov. 



(Plate xxxv., fig. 2, and fig. 53.) 



Sponge small, delicate; of indeterminate habit; 

 probably consisting, in most cases, of compressed up- 

 s^ro^vths arising from a thin encrusting base. Oscula 

 indistinguishable, perhaps absent. Skeleton an irregular 

 sub-renieroid reticulation of thin pauci- or unispicular 

 spon gin-fibres, with meshes the sides of which are 

 usually of not more than a spicule'' s length. Ouasi- 

 ■echinating spicules are of occasional occurrence. Aux- 

 iliary spicules are scattered interstifially — in some parts, 

 sparsely; in others, in dense profusion. Megasclcres : — 

 (/.) Straight or {seldom) slightly curved pri}icipal styli, 

 cylindrical throughout the greater portion of their length, 

 slightly inflated at the base and gradually tapering to a 

 point, attaining a size of igo x 12 ^; (//.) auxiliary sub- 

 tylostyli with a maximum size of joo x j.^ \i. Micro- 

 scleres : — (/.) Palmate isochelce 10 ]i long: (;'/.) bow- 

 shaped toxa, 80 X J p in maximum size. 



1 Dondy— Proc. Roy. Soc. Vict., vii. (n.s.), 1895, p. 246. 



