Classification of the Hpongida. 143 



Group 14. Dictyalia. 



The same, but with the horny element of the fibre decreased 

 and the spicular element increased*. 



Family 4. Pseudochalinida. 

 Group 15. Digitifera. 



The same as " Digitata," but cored with foreign objects, 

 alone or more or less mixed with "proper spicules" (viz. the 

 simple acerate) in the same individual. 



Group 16. Fistulodigitata. 

 The same as the foregoing, but tubular. 



ECHINONEMATA. 



Family 1. Ectyonida. 



Group 1. Pluriformia. 



Sarcode pale tawny, or pink, or purple throughout. Skele- 

 ton composed of a reticulation of horny, anastomosing, trans- 

 parent fibre of a pale yellow colour, echinated with proper 

 spicules externally and cored with proper spicules internally. 

 Fibre of two kinds (viz. vertical or large, and horizontal or 

 small), often passing into fenestrated flattened fibre, in which the 

 two kinds become indistinguishable ; often terminating on the 

 surface in a reticulated form, whose interstices are more or 

 less filled by tufts of projecting echinating spicules, based 

 upon the surface of the fibre sometimes to such an extent as, 

 by contact, to form a uniform continuous crust. Surface often 

 growing outwards into characteristic projections of a massive 

 tubercular or compressed form, which, interuniting with each 

 other, produce a clathrous structure. Vents for the most part 

 small, numerous, and indistinct, consequent on the number of 

 the excretory canal-systems, of which they are respectively 

 the outlets. Spicules, as before stated, of two kinds, viz. 

 axial and echinating : the latter smaller than the axial 

 spicule, for the most part club-shaped, spinous, having its 

 large end imbedded in the surface of the horny fibre. Axial 

 spicule for the most part different in form from the echinating 



* Here it is that the Raphidonemata run into the Holoraphidota, so 

 much so that there is a species of Reniera {fibula, Sdt.) which at Ceylon 

 is a Reniera and at the Cape a Chalinia, according to our empirical 

 distinctions of the two orders mentioned. 



