Zoological Society. 223 



the cylinder, but in opposite directions. The strongest fibres are 

 the longitudinal and transverse ones, which are arranged at intervals 

 of about a line and a half, and mark out regular square spaces 

 of the same diameter : these spaces are kept of pretty equal size 

 throughout the cone, from the circumstance of the longitudinal fibres 

 diminishing in number as the cone decreases in size ; the mode of 

 diminution is not, however, by abrupt termination, but by the gra- 

 dual convergence and final interblending of two contiguous longitu- 

 dinal fibres, and the regularity of the interspaces is therefore disturbed 

 at the intervals of such converging fibres. The fibre resulting from 

 this union of two fibres bears a proportionate thickness to the addi- 

 tional material entering into its composition. The nature of such 

 material is demonstrated at the apex of the cone by the resolution 

 of the longitudinal fibres into their component filaments, each of 

 them dividing at about two-thirds of an inch from their extremity 

 into a fasciculus or pencil of extremely delicate, stiff, glistening, 

 elastic threads, resembling the finest hairs of spun glass. The trans- 

 verse fibres, in like manner, are resolved at the truncated apex of 

 the cone into their component filaments, which intersect those pro- 

 ceeding from the longitudinal fibres, as well as similar pencils from 

 the oblique filaments, the whole forming an irregular silky tuft, which 

 almost closes the apical aperture of the cone. 



" The longitudinal fibres are external to the transverse ones, to 

 which they are connected by both the spiral fibres, and by smaller and 

 less regular intersecting fibres at the angles of the squares ; the area of 

 each square is thus reduced more or less to a circular form : at about 

 one or two inches from the apex, these connecting reticulate fibres 

 begin to rise in the form of narrow ridges from the general surface 

 of the network, and sooner on the convex than on the concave side 

 of the bent cone. These ridges at first are short and interrupted ; 

 they are then more extended, but irregular in their course, some 

 being transverse, others undulated or curved ; but as they approach 

 the base of the cone they are continued into broader ridges, which 

 follow, with more or less regularity, the course of the oblique spiral 

 fibres ; the broadest of these ridges would measure two lines and a 

 half. Their structure presents an extremely fine and irregular net- 

 work, disposed, for the most part, in two plates, which converge as 

 they recede from the general wall of the cone, and terminate in a 

 sharp and well-defined edge. The component fibres of these reticu- 

 lations, like those of the main network, are resolved into the fine 

 silky filaments above mentioned. The fibres of the coarse irregular 

 network which closes the basal aperture of the cone, and which con- 

 stitutes the main characteristic of this Alcyonoid sponge, appear to 

 be directly continued from, and, as it were, to include all those which 

 enter into the composition of the longitudinal, transverse and ob- 

 lique fibres of the wall of the cone ; the frill-like ridge above de- 

 scribed defining the line of transition from the one to the other. 

 The inner surface of the reticulate parietes of the cone is even ; not 

 interrupted by any ridges or processes like those on the outer sur- 

 face. The number of the longitudinal filaments at the base of the 



