46 TRIONYX. 



appendages diverge like the letter V. One of Pennant's 

 figures is from the living specimen, where the skin of the 

 under part is thin and venous. The specimen which he 

 gave to the Royal Society is now in the British Museum. 



T. spinifenis, of Lesueur, in the Paris Museum, is smaller, 

 and the two hinder sternal tubercles are separate and ovate. 

 The head and back brown, often varied with irregular pale 

 spots ; limbs yellow spotted and lined with black. The back 

 is sometimes varied with eyed spots. 



The Great soft-shelled Turtle, Bartram Trav. 645 cop, 

 Magaz. Reise, x. t. Test. Bartrami, Daud, and Test, verru- 

 cosa, Schoepf, Cheli/s, spec. Geoff, appears to be only a cari- 

 catured figure of Trion.ferox, in which the artist has added 

 two claws on each foot. 



2. Trionyx imiticus, [Armless Triojiyx.) — Testa elliptica 

 levissima, antice cum collo continua, dorso centro depresso, 

 sterno 4 calloso, callis 2 posterioribus conjunctis. 



TrionTjx muticus, Lesueur, Mem. Mus. xv. 257 t, 

 (v. Mus. Par. 3 Spec.) 



Habit, in America Boreali. 



Length 8|-, breadth 7i inches ; perhaps young. The 

 figure of the sternum given by Lesueur agrees with Pen- 

 nant's specimen better than his figure of the former species; 

 but the front and hinder margin of the specimen is warty, 

 and the sternum doubtless varies by age. 



3. Trionyx Nilotkus, [Egyptian Trionyx.) Testa supra 

 subconvexa viridi albo punctata, antice leviter undulata, dorso 

 centro sub-convexo osse nuchali lato transverso, sterno 

 4-calloso, callis lateralibus ovato quadrangularibus, posticis 

 equilateris triangularibus. 



Test, triunguis, Forsk. Anim, 18. Test. Niloticus, Shaw. 

 Trionyx Egijptiacus. Geoff. Ann. Mus. xiv. t. L (part cop.) 

 Guerin. Rept. t. L f . 7 ; Rept. Egyp. t. \. 



Jun. "Lineadorsaliserieduplicipunctorum ornata," Geoff. 

 Test, memhranaceus, Blumenb. ? Schneider, Schild. t. L? 



Habitat in Africa Boreah, Nilo, (v. Mus. Brit.) et 

 Congo? (v. caput, Mus. Col. Surg.) 



The lateral callosities are narrow and truncated externally 

 and rather dilated, obliquely truncated and rounded on the 

 angle in the inner edge : the hinder callosities are equila- 

 teral! y triangular, slightly rounded on the outer edge, and 

 placed a little obliquely. The margin of the very old spe- 



