CHELONIA. 793 



tubular nostrils. Toes broadly webbed. Claws moderately strong. Tail not long, 

 projecting in both sexes beyond the fleshy carapace, but longest in the male. Cara- 

 pace an elongated oval, with a vertebral ridge more or less prominent, with the cara- 

 pace external to this marked on either side, with two to tlu-ee raised wavy lines or 

 rudimentary ridges, the line next the vertebral ridge being the longest, the others 

 external to it more interrupted. A swelling over the hinder portion of the nuchal and 

 inner portion of first costals. The nuchal flap of the cartilaginous carapace covered 

 with transverse series of elongated eminences placed side by side ; the broad hinder 

 portion of the fleshy carapace covered with about thirteen longitudinal rows of Httle 

 somewhat backwardly pointed fleshy knobs, one longitudinal series being continuous 

 with the vertebral ridge and others with the finer wavy lines already described. 

 These knob-like eminences are continued more or less over all the cartilaginous area 

 and osseous carapace, in longitudinal parallel lines. The sculpturing of the carapace is 

 somewhat coarse, and the raised reticulating lines tend to enclose circular depressions. 

 The cartilaginous area of the plastron has the general characters in Trionyx. The 

 callosities are well developed, but in the female figured, it will be observed that 

 a considerable area was still open in the centre. The epiplastra are rather long and 

 slender ; they do not meet below on the entoplastron, which has moderately divergent 

 rami, and is characterized by being somewhat feeble and does not show any trace 

 of the growth of a sculptured surface. The other plates are broadly covered with 

 the callous growths, and the sculpturing adheres to the same type as on the carapace, 

 consisting of a rather coarse reticulation of raised lines enclosing spaces, the lines 

 tending on the hyo- and hypoplastral pieces to follow the outline of the inner and 

 outer margins of these plates,^ and the outlines of the xiphiplastron. The latter 

 plates tend to meet in the mesial line anteriorly, but they are slightly divergent 

 posteriorly. 



In the young, the vertebral ridge on the carapace is well pronounced, and tends 

 to become double and to have a finely nodose appearance. The Hues or fine ridges 

 also are more regular and parallel, and each consists chiefly of a longitudinal aggre- 

 gation of Httle fleshy eminences which on the hinder portion of the cartilaginous 

 carapace are larger and more apart and somewhat spinose on their hinder margins. 

 The swelling of the nuchal and costals is present. In the young figured, the sculp- 

 tured callosities of the plastron have not yet appeared. 



Inches. 



Greatest length of osseous carapace 10 



,, breadth of „ „ 8 



Length from tip of epiplastrons to end of xiphiplastron 10'20 



Breadth of plastron greatest 9*50 



Length of the 15 caudal vertehrte $..... 6'50 



The upper surface of the head and neck yellow, reticulated on the head, with 

 broad black interrupted lines not extending on to the under surface, nor passing 

 below the upper half of the upper lip. The portion behind the occiput, and the 

 upper sm'face of the neck black-spotted, in the adult more or less finely reticulated. 



^ They are represented too concentric in the plate. 



D 5 



