398 ' PROF. J. A. TilOMSOX AND MR. W. D. HENDERSON ON [Apr. 10, 



Towards the mouth of the Bay, on the noi-th side, there are 

 three fathoms of water at low tide, and here anobher marine 

 Phanerogam is abundant, one with a strong hard I'hizome and 

 stems, a tuft of opposite leaves arising from the top of each of the 

 latter. On these hard stems gi-eat quantities of bright blue 

 encrusting forms were brought up, and among them quantities of 

 brown Nephthyid*, &c. The quantity and variety of these were 

 most striking, Alcyonarians of one kind or another coming up 

 literally by the sackful at many hauls. This spot was almost the 

 richest in Opisthobranchs and other interesting forms tliat I ever 

 dredged in. 



Kokotoni Harbour is a broad lake- like enclosure between the 

 Island TuMBATU and the north-western shores of Zanzibar. The 

 village, now very insignificant, lies at its south-western corner. 



A bank in the narrow southern entrance to the channel upon 

 which corals grow, is a garden of Alcyonarians of wonderfvil 

 variety and beauty, but on the whole the shores are rather bai-ren 

 even of Xeniidse. Dredging reveals a current-swept bottom 

 practically barren of all life over the greater part, but in shallower 

 water (5 fath. and under) off the north-west shores an area of 

 great wealth was found, where Pteroeides is common. 



On the mainland Mombasa harbour and the reefs in its vicinity 

 are very barren, even Alcyonaiia occurring but sparsely and 

 corals being absent. Sii- Charles Eliot had seen a good deal of 

 the coast befoi-e I arrived and had selected Wasin harbour as 

 the best collecting-ground. This is a canal-like channel separating 

 the island of Wasin from the mainland ; the Anglo-German 

 boundary is a few miles south of this. The lichness of the shores 

 was found to extend over the whole bottom of the channel. The 

 di'edge generally filled with Alcyonaria and sponges in a few 

 minutes, a variety of branched and massive forms occuriang in the 

 inner or western parts about the Government station of Shimoni, 

 while towards the open sea great quantities of a Telesto, generally 

 more or less overgrown with a red sponge, were brought up time 

 after time, while large colonies of Lophogorgia with commensal 

 ophiuroids and cirripedes, the latter embedded in the coenenchyme, 

 are common. 



One expects corals, not Alcyonaiia, to be the most conspicuous 

 and abundant form of animal life in tropical seas, but when it is 

 considei'ed tliat large strips of the East African shores are bare of 

 coral, whereas Alcyonaria occur almost ev'erywhere, and in many 

 places with the profusion one associates with corals, their claim 

 to be of first importance is seen to be well established. 



The corals are easily first in the Red Sea, where they abound 

 practically everywhere. Alcyonaria, having the same macroscopic 

 characters as those of East Africa, are present in magnificent 

 abundance, but I have not seen numerous Clavulariidse, and all 

 the Xeniida? seemed to be brown or grey, not green or blue. 



