772 EEPTILIA. 



Tetraonyx affinis, Cantor, Journ. As. Soc, Bengal, vol. xv, 1847, p. 612 [pars). 



Tetraonyx baska, Dumeril, Cat. Meth. Rep., p. 15, 1851. 



Clemmys longicoUis, Strauch, Chelon. Stud., 1862, p. 33; id. Vertheil. der Schildkr. 1865 p. 87. 



Snout pointed and turned upwards, the upper surface concave between the 

 anterior half of the orbits, convex behind this. The facial portion is much more 

 pointed, up-turned and narrower than in B. lineata, and the nostrils are more 

 tubular. An elongated shield between the orbit and the anterior upper half of the 

 tympanum, with a very narrow elongated shield below it and the aural border. 

 Tympanum covered with rather small scales, arranged somewhat in concentric 

 circles. The skin granular on the neck and on other parts of the body as in 

 B. lineata, with similarly defined scales. The jaw is feebly serrated and sKghtly 

 notched anteriorly. 



The general colour of the upper surface of the head and neck in the female is 

 olive- green, with the horny covering of the jaws yellow, the under surf ace of the neck 

 being also more yellow than the upper surface ; the limbs and tail being dark ohve- 

 green. The claws yeUow. The upper sui-face of the shell is a uniform olive-brown, 

 the under surface yellow. 



The shell has no ridge in adult life, but the young has a rather pronounced 

 vertebral ridge. The shell is not so elongately oval as in B. lineata and is more 

 expanded posteriorly and has more reverted marginals. It is also generally more 

 arched from side to side in its anterior half ; broader before and much fuller over the 

 region of the fl.rst and second vertebrals and first costals, than in the generality of 

 shells of B. lineata. It attains its greatest depth between the second and third 

 vertebrals. It is distinguished from B. lineata by the more quadrangular form 

 of its vertebrals^ but more especially by the absence of the fourth elongated verte- 

 bral of that species. 



The nuchal is not so broad posteriorly as in specimens of the same size of 

 JB. lineata. Like that species, the first vertebral has divergent lateral margins, but 

 the hinder margin, if it is at all concave, is not so much so as in B. lineata, and it 

 is occasionally quite straight. It is broader than long, its greatest breadth being 

 between the costo-marginal angles, and its posterior breadth also either exceeds or 

 equals the length. The shield is marked by a feeble longitudinal swelHng. The 

 second vertebral is also broader than long. Its first costal margin is directed back- 

 wards and outwards and is nearly straight, the second costal border being directed 

 inwards and backwards from the former, with a sinuous outline. The posterior 

 border is very faintly concave from behind forwards. The greatest breadth of the 

 shield is attained between the two costals, the breadth of the posterior border 

 scarcely equalling the length of the shield. The third vertebral is also a little 

 broader than long, and only slightly broader in its anterior than in its posterior 

 margin which is backwardly concave. Its greatest breadth is attained between the 

 second and third costals, and if its slight outward projection at that point is 

 omitted, the two sides of the third plate are nearly parallel, but a little posteriorly 

 convergent. The fourth is considerably broader than long, and the front margin 



