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Show 1870.] DR. .I. E. GRAY ON CYCLANOSTEUS SENEGALENSIS. 717 6. Notes on a Specimen of Cyclanosteus senegalensis living* in the Society's Gardens. By Dr. J. E . G R A Y , F.R.S. (Plate XLIII.) The Society acquired by purchase, from a London dealer, on the 30th August, a fine living specimen of Cyclanosteus senegalensis, Gray (P. Z. S. 1864, p. 21), which is certainly the first I have ever seen, and, I believe, the first seen alive in Europe; and it is a very interesting animal, as it has the form of the freshwater Tortoise with all the other characters of the Mud-Tortoises or Soft-shield Turtles (Trionychidse). The specimen must be nearly adult; but it is not quite so large as the dorsal shield with its margin which the British Museum received from the Earl of Derby, who obtained it from his collector, Mr. Whitfield, from Gambia, which is figured under the name of Cyclanosteus petersii in the 'Catalogue of Shield Reptiles,' tab. 29. It has all the sternal callosities developed as in that figure; but the hinder pair, instead of being round and small, are considerably larger and oval. The odd or nuchal bone is placed in the margin of the cartilaginous shield, and separated from the front of the dorsal bony disk by a broad flexible space. The animal is ovate, depressed; the back is convex, like a large Batagur or Emys, with a very broad, hard, cartilaginous margin, which is thin, but rounded on the edge; the hinder part of the f margin is very broad and expanded, slightly concave on its upper surface, and bent up like that of several of the freshwater Tortoises. The whole upper surface is covered with a thick, smooth, blackish-olive skin, which completely hides the rugosities on the bony disk, and gives the animal the appearance of the skin of a porpoise or dolphin. The under surface is covered with a similar skin, but of a pure white colour, the white on the underside of the margin forming a narrow edge to the dorsal disk ; the underside is equally smooth as the back, except over the callosities, which are tuberculated in concentric circles. The skin between the odd bone in the margin and the front of the bony dorsal disk is concentrically wrinkled. The head is rather large, olive or blackish, with pale spots on the upper part of the sides. The nose produced, black; nostrils flesh-coloured, small, circular, separated by a broad septum, and with a small internal lobe on the outer side of each. Eyes lateral; pupil small, black; iris greyish, without any spot on the sides ; the lower eyelid larger, thin, pellucid, whitish. The hinder part of the fore feet very broad and expanded, lobulated on the edge, and folded together when contracted, with the three claws on the front part of the foot. The front of the sternum and its flaps as broad and of the same shape as the dorsal disk; the hinder part of the sternum broad ; the lateral flaps large and separated from the hinder soft part of the sternum by a deep notch on each side. This animal is interesting as being intermediate in form between |