ioS 



N. ANNANDALE 



more or less circular outline on the leaves of water-plants ; consistence 

 soft, friable, very delicate ; dermal membrane extremely delicate. 

 Often, owing to the dropping out of the gemmules, the sponge has 

 a honeycomb-like appearance. In alcohol there is practically no 

 colour except that derived from the gemmules, which are yellow. 

 SKELETON quite incoherent. 



SPICULES. Skeleton spicules long, very slender, sharply pointed, 

 smooth but occasionally a little irregular in outline, as a rule feebly 

 curved. Gemmule spicules long and slender ; the rotulae feebly 

 developed, consisting merely of a circle (or more usually of a couple 

 of circles) of more or less recurved spines, which arc considerably 

 longer and stouter than the straight or nearly straight spines sparsely 

 scattered on the shaft ; the shaft more or less curved, of the same 

 width throughout. Free microsclercs absent. 



GEMMULES relatively large and numerous, adherent to the 

 support of the sponge but not strongly so ; the granular layer well 

 developed except on the extreme top of the gemmule, which presents 

 an almost bare surface ; the spicules arranged vertically and 

 tangentially in the granular layer (from which they often project 

 considerably), in a single row ; the single aperture situated at the 

 base of the gemmule, provided with a short, stout, straight foraminal 

 tubule, which expands at the distal extremity. 



Measurements : — 



Length of skeleton spicule O.289-0.391 mm. 



Greatest diameter of skeleton spicule 0.008-0.01 ,, 



Length of gemmule spicule 0.076 ,, 



Diameter of shaft of gemmule spicule 0.004 



Diameter of rotule of gemmule spicule 0.002 ,, 



Diameter of gemmule 0.425-0.561 „ 



HABITAT : — Kasumi-ga-Ura, Hitachi Province, Japan (Dr. A. Oka) ; 

 November 1906. Some specimens from the locality taken a month earlier 

 probably belong to the same species but arc devoid of gemmules. 



