148 Mr. H. J. Carter on Holasterella and Hemiasterella. 
gradually sharp-pointed, l-25th inch long by 1-900th inch 
thick in its greatest dimensions (fig. 10) ; 2, flesh-spicule, stel- 
liform, rays straight, smooth, sharp-pointed, variable in num¬ 
ber, from four to ten, of which seven appears to be the average 
(fig. 10, a, b), centre or point of junction of the rays some¬ 
times with (fig. 10, c) and sometimes without a slight infla¬ 
tion or body, largest stellate about 1-600th inch in diameter, 
and of all sizes below this : the former chiefly confined to the 
internal structure, and the latter to the incrustation, but both 
equally mixed throughout the interior. Size of specimen, 
which is imperfect both above and below, 5 inches long; orifice 
2-| inches in diameter; lower end, which has been broken off, 
solid, 1^ inch in diameter. Cavity conical, nearly as deep as 
the length of the specimen in its present state. 
Hah. Marine. 
Loc. -? 
Obs. Examined in the dried state. It will be observed from 
the description that this sponge is very like the last, although 
sufficiently different in the acerate form of the skeleton-spicule 
&c. to be designated u affinisf but must, of course, be placed 
in the same genus. The remarks applied to the foregoing 
specimen equally apply to this. (Bk. coll. no. 679.) 
In my “ Observations ” on Mr. Thomson’s fossil sponge 
I have noticed that Xenospongia patelliformis is half com¬ 
posed of bodiless stellates similar to those of Holasterella 
confer ta, together with a long, setaceous, acuate spicule, by 
which, on the other hand, it becomes in spiculation more 
closely allied to Hemiasterella typus ; but as Xenospongia 
patelliformis , by reason of its peculiar form and mode of 
growth, cannot come under the genus Hemiasterella , it might 
be made the type of a separate group among the Suberitida, 
together with Halicnemia patera , Bk. (Mon. Brit. Spong. 
vol. iii. pp. 31, 32, pi. xv.), although the latter has a spined 
acerate flesh-spicule instead of a stellate. 
Placospongia melobesioides , Gray (Proc. Zool. Soc. 1867, 
p. 128),= Geodia carinata , Bk. (ib. 1874, pi. xlvi. fig. 1 &c.), 
is another sponge of this kind ; that is, its spiculation chiefly 
consists of the siliceous ball, like that of Geodia, and a 
pinlike spicule ; but being accompanied by a minute spini- 
globate ball like that of Chondrilla nucula , together with a 
zigzag or spinispirulate one like that of the Suberitida, to say 
nothing of its peculiar form and mode of growth, it too must 
be made the type of a distinct group in this family. The 
II siliceous ball ” of Geodia also commences in a minute, simple, 
star-like spicule, which in abnormal development is often 
