294 
Mr. II. J. Carter’s Contributions 
by the generic name of u Trikentrion ” (Esper’schen Spon- 
gien &c. in der zool. Samml. der k. Universitat Erlangen). 
Finally, Mr. Sollas, in January last, published an account of 
it from a specimen in the Bristol Museum, under the name of 
Plectronellci papillosa, as “a new Genus and Species of Echi- 
nonematous Sponge” (‘Annals,’ 1879, vol. iii. p. 17, pis. 
iv.-vi.). 
Of this sponge there are several specimens in the British 
Museum, whose spiculation consists of tufts of smooth, curved, 
acerate spicules attached to indistinct or ill-defined fibre, echi- 
nated with triradiate spicules, one of whose arms is cylin¬ 
drical, obtuse, spined especially over the free end, and three 
times the length of either of the other two, which are com¬ 
paratively short, smooth, sharp-pointed, and fixed in the 
sarcode, the long, spined arm being the echinating one (PI. 
XXVII. fig. 13, a, b , c, d). 
All the specimens come from the western coast of Africa; 
and each bears my running no. 252, D, b, 1, also respectively 
the nos. 31 a, 41. 5. 13. 37, and 72. 10. 9. 1, to the last of 
which is added “ Volta, Fantee, presented by Governor 
Ussher.” With them will be found another but much smaller 
sponge, numbered 252 a, D, 7q 2, and 48. 10. 4. 6, which, 
differing from the foregoing in spiculation and general form, 
though also from the west coast of Africa, claims the fol¬ 
lowing distinctive appellation and description. 
Trikentrion Iceve , n. sp. (PI. XXVII. figs. 9-12.) 
Specimen a small globular bunch of short, cylindrical, 
obtuse branches, arising from the subdivision of a small, 
equally short, round stem. Colour now purplish. Texture 
loose, compressible. Surface even, reticulate, slightly setose. 
Structure throughout fibro-reticulate, charged with the spi¬ 
cules of the species (PI. XXVII. fig. 10). Spicules of three 
forms, viz,:—1, long, setaceous, acuate, smooth, curved, sharp- 
pointed, l-33rd by l-3600th inch in its greatest diameters 
(fig. 9, a) ; 2, short, acerate, smooth, curved, sharp-pointed 
(fig. 9, b ), 1-120th by 1-3600th inch, sometimes bent in the 
middle (fig. 11, a), or inflated in the centre (fig. 11, b), occa¬ 
sionally acuate (fig. 11, c); 3, echinating spicule, triradiate, 
arms cylindrical, obtuse, about 1-200th by 1-2000th inch in 
their greatest dimensions, for the most part equal in length 
and radiating at nearly equal angles from each other, the 
echinating arm alone spiniferous, chiefly over the free extre¬ 
mity, the two others smooth (fig, 9, d , and fig. 12, «-c), occa¬ 
sionally quadriradiate (fig. 12, b, c). No. 1 (fig. 10, a) pro¬ 
jects setaceously from the midst of a tuft of very thin acuates 
