Catalogue of N on- Calcareous Sponges. 51 



well-developed ovoid head at one end and several well-developed, 

 recurved, shai-p teeth at the other. The usual number of teeth 

 appears to be live, but I should doubt if this is constant. The 

 spicule is about 0-16 mm. long, and the shaft is scarcely 

 0'002 mm. thick for the greater part of its length, but increases 

 in diameter at each end ; the teeth are about 0-004 mm. long. 

 These " grapnel-spicules " are not echinating ; indeed, there is no 

 fibre for them to echinate, but they are extremely numerous. 

 They occur scattered irregularly and also in loose bundles, in 

 which they lie parallel to one another, with some of the grapnels 

 at one end of the bundle and some at the other, each spicule 

 extending the whole length of the bundle, or very nearly so. 



As might naturally be expected, a few spicules of the sponge 

 on which the specimen has grown may occur as foreign bodies. 

 I have found no microscleres. The soft tissues are densely 

 charged with spherical cells about 0*006 mm. in diameter. 



This is one of the most remarkable sponges in the entire 

 collection. 



£2 



