124 Mr. H. J. Carter on 



cumference only to the object on AA'hich it may be fixed. 

 Consistence hard. Colour verdigris-green or bhie thronghout. 

 Surface smooth. Vents irregularly scattered over the surface. 

 Spicules of five forms, together with a large pigmental cell, 

 viz. : — 1, body-spicule, as usual, a long acerate, 288 by 2|- 

 6000ths in. ; 2, zone-spicules or tetractinellids, arms simple, 

 remarkably long, at first projected for a little distance ante- 

 riorly and laterally, and then horizontally for the rest of the 

 course, head 106-6000ths in. in diameter, shaft 344 by 

 3-6000ths ivj. ; 3 and 4, anchors and forks, each with short 

 thick arms and, as usual, long shafts, the former plenti- 

 ful, the latter small and scanty ; 5, fiesh-spicules, stellates of 

 two sizes, the largest about 6- and the smallest 2-6000ths 

 in. in diameter, rays spined verticillately. Pigmental cell 

 globular or slightly elliptical, distinctly nucleated and granu- 

 liferous, granules brown ; cell 4-6000tlis in. in diameter, 

 granules strongly marked, 1- 6000th in. Structure compact, 

 consisting from without inwards of a fibrous dermis in which 

 are imbedded the pigmental cells (which, from their compara- 

 tively large size, are striking objects), together vvdth the smaller 

 stellates, the outer points of the body-spicules, and the heads 

 of the zone-spicules all mixed together. Size variable, under 

 an inch in diameter. 

 Depth about 6 fath. 



Ohs. There are upwards of a dozen specimens of this sponge 

 under the size above mentioned down to that of a pea, and all 

 attached to different objects, sometimes one or two together or 

 following each other, especially on the stalks of Chalina 

 polychotoiva. Like the foregoing, they do not part with their 

 colour on being kept in spirit. Direct communication between 

 the pore-structure and the cavities of the excretory canals is 

 presented at their circumference. 



30. Stelletta mamiJUfonnis. 



Globoconical, mamilliform, sessile. Consistence tough, 

 dense. Colour whitish, colourless. Surface rough, being- 

 more or less covered with grains of sand agglutinated to the 

 dermis. Vent single, terminal, large. Spicules of five forms, 

 together with a pigment-cell, viz. : — 1, body-spicule, as usual, 

 a long large acerate, 345-GOOOths in. in length; 2, zone- 

 spicule or tetractinellid, arms at first simple, then bifurcate, 

 the simple or proximal part projected anteriorly and laterally, 

 and the forked part horizontally, head 84-6000ths in. in 

 diameter, shaft 344 -6000ths in. long; 3 and 4, anchors and 

 forks present as usual, with long slender shafts and more 

 slender arms than those of the foregoing species ; 5, flesh- 



