178 PLATE LXX. 



central canal and three gemmules attached to the 

 skeleton fibre. X 250 linear. 



In a specimen examined since the publication of the 

 description of this sponge in vol. ii, p. 380, ' Mon. 

 Brit. Spongiadse,' I have observed numerous gem- 

 mules attached to the fibres of the skeleton and to the 

 inner surface of the dermal membrane. They are 

 membranaceous and aspiculous, oval or spherical, and 

 they vary considerably in size, some of them being not 

 more than half the diameter of the largest ones. Their 

 general appearance is very like that of the greater 

 number i 

 sponges. 



number of the gemmules of the Halichondraceou 



DiPLODEMiA VESICULA, BowerhanJ,-. 



Vol. ii, p. 357, ' Mon. Brit. Spongiada;.' 



Fig. 12. — Represents the type-specimen of the 

 species on the fragment of a valve of a pec ten. A 

 group of the ovaries is to be seen opposite (a). 

 Natural size. 



Fig. 13. — One of the spicula in the fibrous part of 

 the skeleton. X 250 linear. 



Fig. 14. — A spiculum from the reticulated part of 

 the skeleton. X 250 hnear. 



In vol. i, Plate XXXVI, fig. 377, a portion of the 

 compound reticulate skeleton is represented exhibiting 

 the intermixture of the spicnlo-reticulate skeleton with 

 the hetro-spiculate fibrous one. X 108 linear. 



In Plate XIV, fig. 273, the same volume, there is a 

 small jnece of the hetro-spiculated keratose fibre of 

 the skeleton figiu'ed. X 175 linear. 



In Plate XXIII, fig. 324, two of the ovaria arc 

 represented, x 83 linear. 



