BY E. F. KALLMANN. 



663 



irregular agglomeration of spicules." It is obvious that the 

 "tracts of spicules" cori-espond to vertical transections of the 

 lamellse. 



Where the main skeleton 

 abuts on the surface of the 

 sponge (i.e., along the sur- 

 face-ridges), the terminal 

 spicules of the skeletal 

 fibres project slightly be- 

 yond the dermal membrane, 

 and along with these pro- 

 jecting fibral spicules are 

 occasional small clusters of 

 much shorter and slenderer 

 diactinal spicules which are 

 perhaps to be regarded as 

 special dermal megascleres. 

 Elsewhere (i.^., within the 

 surface-grooves) the dei'mal 

 membrane overlies exten- 

 sive subdei'mal spaces, and 

 is generally free from mega- 

 scleres. 



Afegascleres. — (i.) The 

 spicules of the skeleton- 

 reticulation are somewhat 

 angulately curved oxea(and 

 occasional styli), which in 

 some specimens are of 

 nearly uniform diameter 

 to within a comparatively 

 short distance of their ex- 

 ti'emities and generally are more or less irregularly pointed (often 

 somewhat blunt-pointed, and occasionally approximating in form 

 to strongyla), while in other specimens they taper very gradually 

 to the extremities {i.e., are more or less fusiform) and with rare 



Text-fig. 20. — Higgin-na coralloides var. 

 mctJiAalis. a, megascleres of the fibres; 

 1), interstitial megascleres ; c, dermal 

 megascleres; d, spinecl mieroxea; e, im- 

 mature microxea. 



