The Tanganyika problem; an account of the researches undertaken concerning the existence of marine animals in Central Africa . microscleres are nowhereconnected with the fibres, but lie absolutely free in the tissues. The Spongin.—The spongin is not so highly developed in Spongillatanganyika as in Spongilla moorei. The former, therefore, in this respect resemblesmore closely the ordinary7 species of Spongillicke than the latter appears to do. Thespongin does not appear to extend to the surface, and the layer which covers thefibres is correspondingly thin. The greater development of spongin occ
The Tanganyika problem; an account of the researches undertaken concerning the existence of marine animals in Central Africa . microscleres are nowhereconnected with the fibres, but lie absolutely free in the tissues. The Spongin.—The spongin is not so highly developed in Spongillatanganyika as in Spongilla moorei. The former, therefore, in this respect resemblesmore closely the ordinary7 species of Spongillicke than the latter appears to do. Thespongin does not appear to extend to the surface, and the layer which covers thefibres is correspondingly thin. The greater development of spongin occurs at pointswhere the fibres branch or reunite, and at the places where the connecting spiculespenetrate the fibres. The —Though there was but a small piece of this sponge, ithappened to contain several gemmules. These are devoid of spicules, but aresurrounded by the ordinary skeletal spicules and the microscleres ; they possess athin coat, as in Spongilla moorei, and are spherical and of small size. As regardstheir cellular contents, they present the ordinary characters of the 1 (I 0 « I A • . i. , I Fig. 3. «., A portion of the skeleton ol anvika. />., Spicule ilia Tar, 32o THE TANGANYIKA PROBLEM. AFFINITIES. This subject must be considered from two aspects. Inthe first place, the character of the gemmulse must be takeninto consideration, since the grouping of the Spongillidaeinto the three sub-families, Spongillinae, Meyeninae and Lubo-mirskinae, and the division of the sub-families into genera,usually adopted, depends on these characters. In thesecond place, the spicules are of great importance, as pre-senting a close resemblance to the spicules of Lttbomirskiaintermedia var. a (Dybowski, cf. pi. iv., fig. 3, b), whichbelongs to the sub-family Lubomirskinae. (A) The Gemmule.—The gemmule of Spongilla tan-ganyikcs lacks the amphidiscs which surround the gemmuleof the Meyeninae. It therefore appears that the speciescannot belong to th
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