5. Spongilla travancorica*, Annandale.
Spongilla travancorica, Annandale, Rec. Ind. Mus. iii, p. 101, pl. xii, fig. 1 (1909).
Sponge small, encrusting, without branches, hard but brittle; its structure somewhat loose; colour dirty white. Dermal membrane in close contact with the skeleton; pores and oscula inconspicuous. Surface minutely hispid, smooth and rounded as a whole.
Skeleton consisting of moderately stout and coherent radiating fibres and well-defined transverse ones; a number of horizontal megascleres present at the base and surface, but not arranged in any definite order. No basal membrane.
Fig. 11.—Microscleres of Spongilla travancorica. A=Gemmule-spicules; B=flesh-spicules (from type specimen), × 240.
Spicules. Skeleton-spicules smooth, pointed at either end, moderately stout, straight or curved, sometimes angularly bent; curvature usually slight. Free microscleres abundant in the dermal membrane, slender, nearly straight, gradually and sharply pointed, profusely ornamented with short straight spines, which are much more numerous and longer at the middle than near the ends. Gemmule-spicules stouter and rather longer, cylindrical, terminating at each end in a sharp spine, ornamented with shorter spines, which are more numerous and longer at the ends than at the middle; at the ends they are sometimes directed backwards, without, however, being curved.
Gemmules firmly adherent to the support of the sponge, at the base of which they form a layer one gemmule thick; each provided with at least one foraminal tubule, which is straight and conical: two tubules, one at the top and one at one side, usually present. Granular layer well developed. Spicules arranged irregularly in this layer, as a rule being more nearly vertical than horizontal but pointing in all directions, not confined externally by a membrane; no external layer of horizontal spicules.
Measurements of Spicules and Gemmules.