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Show 434 PROF. J. A. THOMSON AND MR. W. D. HENDERSON ON [Apr. 10, Family TELESTID^. TELESTO RUPICOLA Miiller. Under this species we have ranked three somewhat different specimens. The first consists of a single axial polyp 141 m m . in length, the lowest part of which is covered by a monaxonial sponge through which the lateral polyps protrude. The colour of the living specimen was yellowish with white zooids. The axial polyp is 1*5 m m . in thickness near the point where it emerges from the surrounding sponge, but at the tip it is only 0*75 m m . The lateral polyps stand at regular intervals of about 6*5 m m . on all sides of the axial polyp; their height varies from 4-4*5 m m . and their basal diameter is 1*1 m m . In the lateral polyps the tentacles are 1*2 m m . in length and about 0*5 m m . in breadth, with numerous pinnules, which have an annulated appearance. On both sides of the base of each tentacle there are two bands of spicules which extend down the anthocodial part and join the spicules of the calyx. On the axial polyp and on the lateral polyps there are eight prominent ridges. This specimen approaches Telesto rupicola of Hickson k Hiles, but there are some differences :- (1) The tentacles of our specimen are longer. (2) The arrangement of the lateral polyps is more regular. (3) It does not very closely resemble Hickson's figure (Willey's Results, pi. 1. fig. 1). W e note, however, the variability of Telesto rupicola as mentioned in Hickson's * Alcyonaria of the Maldives,' pt. i. p. 482, and also in the ' Challenger' Reports, vol. xxxi. p. 262. In the second specimen the axial polyp is 2 m m . in thickness, growing gradually less as it rises higher, and becoming 1*5 m m. near the tip. After treatment with caustic potash the hollow axis is seen to be composed of two types of spicules, some long and slender with few and slight projections, the others short and stout with numerous strong projections. The first type varies from 0*45-0*63 m m . in length and from 0*02 to 0*028 m m . in width; and the second from 0*15-0*2 m m . in length and from 0*02-0*028 m m . in width. The third specimen differs slightly from both the others, but it also seems referable to T. rupicola. Locality. Mr. Crossland notes : " By the kindness of Captain Agnew, R.N.R., I accompanied the steamer sent to overhaul the buoys and chains and found these specimens on the chains of the buoy nearest Zanzibar to the south." TELESTO ARBOREA Wright k Studer. One of the specimens is dark in colour and consists of a few axial polyps. From the axial polyps lateral polyps arise, and among these there are some decidedly larger than the others, which may be the beginnings of axial polyps of the second order. |