REPORT ON THE HEXACTINELLIDA. 173 



body measuring 4 to 5 cm. in transverse and longitudinal diameter. This loose body- 

 was unfortunately very much injured. While the upper funnel-shaped terminal surface, 

 limiting the gastral cavity, is so abundantly penetrated by roundish apertures of variable 

 size that only a network of more or less broad septa and free smooth margins remain, 

 the external, much torn surface is studded with numerous thin and pointed spicules 

 which project freely for 2 to 4 cm. beyond the general surface of the body (PI. LXIX. 

 fig. 1). 



The large spicules of the body-parenchyma consist for the most part of long, rather 

 thin, smooth diacts, which are rough at their ends, and terminate without any marked 

 swelling in a simple conical point. At their centre some exhibit a distinct annular 

 swellino- containing an intersection of the axial canal. Most of the spicules, however, 

 remain uniform and cylindrical throughout. 



Between these long and slightly bent or looped diacts, a varying number of diverse 

 rosettes occur. The majority are rather large discohexasters, in which the moderately 

 short and simple principal rays usually bear four long divergent terminals. The latter 

 are very thin at their base, but increase gradually in thickness towards the exterior, and 

 finally terminate in a relatively broad, convex, transverse disc, which usually bears a 

 fairly large number of marginal teeth (PI. LXIX. figs. 3, 4, 7, 8). In the more strongly 

 developed forms, the thickened external ends of the terminal rays exhibit small irregularly 

 scattered tubercles (PL LXIX. fig. 7). 



Between very weakly developed rosettes of this type, with thin terminal rays 

 (PL LXIX. fig. 3), and rather strongly developed forms, twice or three times as broad 

 (PL LXIX. fig. 4), many transition types occur. 



In addition to the above, we have to note the rather frequent occurrence, especially 

 in the subgastral trabecular spaces, of small plumicomes, in which the moderately short, 

 simple principal rays each bear on their ends a broad convex transverse plate. From 

 the convex external side of the latter, a large number of S-shaped, pointed, terminal rays 

 arise, disposed in perianth-like fashion, and more strongly developed in the outer than 

 in the central portion (PL LXIX. fig. 6). 



The dermal skeleton is formed of oxjrpentacts, in which the tangential rays, inter- 

 secting at right angles, and often somewhat bent, are laterally beset with scattered, slightly 

 curved spines. The radially directed proximal ray, which is usually much longer, and 

 frequently curved with faint undulations, is, on the other hand, either quite smooth, or 

 merely ecpiipped with minute tubercles (PL LXIX. fig. 2). An inconspicuous protuber- 

 ance may be occasionally observed on the distal side of the node of intersection. The 

 gastralia are somewhat rough oxyhexacts, in which the four tangential rays are straight 

 or slightly curved, and conically pointed at their ends. The moderately long, freely 

 projecting ray is either conically pointed as above, or exhibits a slightly clubbed 

 thickening in front of the terminal point, while the usually longer radial ray opposite 



