44 Mr. H. J. Carter on 



composed of uniformly cribrated sarcode densely cliarged with 

 " mortar-spicules " and small triradiates, giving it a rough 

 compact aspect. Pores, the holes of the cribriform structure, 

 all tolerably uniform in size. Vents single, terminal, circular, 

 at the end of each of the individuals ; each provided with a 

 short peristome, and each leading into its own cloaca, wliich 

 corresponds in shape to the form of the individual, but is so 

 much broader than the wall that the latter looks like a mere 

 shell ; holes numerous, small and great, but still tolerably 

 uniform, permitting more or less of the openings of the wall- 

 structure to be seen within them, according to their size; 

 separated by the skeletal structure of the cloaca, which con- 

 sists, like the surface of the body, of small triradiates, but 

 with no " mortar-spicules," Wall thin, about l-30th in. in 

 diameter, consisting of subradial chambers like those of 

 Grantia hirsuta^ but more broken up in their parallelism by 

 the large holes of intercommunication ; covered by the pores 

 of the surface externally, and opening, as before stated, into 

 the holes of the cloaca internally ; mixed in their skeletal 

 structure, which consists of the " articulated " form externally^ 

 and the " inarticulated " one internally, but all comparatively 

 small; thus the inner radiates of the "inarticulated " portion, 

 which are the largest, have their sagittal heads fixed in the 

 cloaca, while their shafts extend outwards horizontally to 

 about the middle of the wall. Spicules of three kinds, viz. 

 acerate, triradiate, and quadriradiate : — 1, acerates, long and 

 short, the former fine, cylindrical, straight, and similarly 

 pointed at each end, and the latter short, minute, more or less 

 sinuous, fusiform, and lance-pointed at one end, about 15 by 

 |-6000th in. ; 2, triradiates, regular and irregular, compara- 

 tively small throughout, the larger, as before stated, on the 

 inner side of the wall, where their shafts average 60-6000ths 

 in. long ; 3, quadriradiates, also regular and irregular in their 

 triradiate portion, provided with a thick, curved, fourth 

 arm. No. 1, in its two forms, is confined to the peristome 

 and cribrate sarcode respectively, where the latter, which 

 are the " mortar-spicules," mingle (as is the wont of the 

 dermal acerate when present) in a larger form with the 

 proximal ends of the peristomes; no. 2 is common to the wall 

 and its limiting layers on each side, viz. the cloaca and the 

 cortical layer on the surface of the body ; no. 3 is chiefly 

 confined to the surface of the cloaca, where its fourth arm, 

 which projects into the interior of this cavity, is thick and 

 curved, but not plentiful. Size of specimen, which, being an 

 agglomeration, is of course very irregular, about 2 in. long by 

 1 in. thick ; the largest individual of the buncli about 1^ in. 

 by 5-24ths in. in its greatest dimensions. 



