Die 
*e 
a 
~ 
and a new Species from Africa. By oy 121 
gemmule [statoblasts] are imbedded, but without penetrati. 
the peripheral part. The trabecul of the framework lie loose 
in the centre. 
The skeleton-spicules have rounded ends and are mode- 
rately curved; very few of them (perhaps one among 200 
ordinary spicules) are seen with pointed ends, but always 
with cylindrical middle part: these are of equal length with, 
but in diameter only half as large as the former. From 4 to 
§ spicules combine to form the thickness of a trabecula. The 
diameter of the meshes may be twice that of a gemmula. 
The one-pored gemmulx possess a considerably thickened 
erust, which (enumerating from the centre outwards) consists 
of a layer of chitine, a stratum of tangential spicules, a mass 
of parenchyma, and a second (outer) stratum of spicules. 
These spicules are half as long as those of the skeleton ; and 
each forms a slender double cone armed with scattered, short, 
pointed spines, and is mostly pointed at its ends. They are 
present only in small number, about 30 to each hemisphere of 
a layer, making a total of 120 in a gemmula. The paren- 
chyma consists of delicate-walled vesicles, polyhedric by com- 
pression, arranged in radiating series of about ten each. In 
the radial direction they are flattened, so that their height may 
amount to half their breadth. 
Measurements.— 
millim 
Diameter of the largest specimen .............. 130 
Height i Ine TI araemiste weed « 50 
Length of the outgrowths upon the surface .... 6 
Thickness bF bf ery dep et Yel 
micromillim. 
Length of the skeleton-spicules .............. 336 
Thickness ‘s Da a Mavs, Soh scaro aa Sessa 28 
Diameter of the gemmuls....... 200. e ee ee ews 308 
Whickness of the entire'crust ).... 00.0.0... 66s. 56 
Tangential diameter of the parenchyma cells .... 14 
Radial diameter i PM ce eno 0) 
Length of the gemmula-spicules .............. 154 
Thickness x Sh AU atvanncr teenies 8:4 
These data accord, so far as a comparison from the descrip- 
tion is possible, with the Spongilla nitens of Carter (Ann. & 
Mag. Nat. Hist. 1881, vii. p. 89) ; only I do not find there any 
statement about the flattening of the polyhedric cells, upon 
which, however, much weight can hardly be laid. Unfortu- 
nately the locality of that species is not known; but from 
their unmistakable similarity to the present form, Carter’s 
specimens may likewise have come from Africa, and not from 
South America as he supposes. 
Ann. & Mag. N. Hist. Ser. 5. Vol. xii. 9 
