510 DR. J. E. GRAY ON THE GENUS ELSEYA. [Mar. 19, 



with a few tubercles. Thorax depressed, dilated and reflexed on the 

 side. Nuchal shield none (or abnormally very small and narrow). 

 Fore legs with a few transverse scales. 



The skull of E. latislernum depressed, broader behind ; forehead 

 and crown flat to the occiput, broad, becoming wider behind ; the 

 tympanic cavity rather produced, of moderate size ; basisphenoid 

 short, broad, transverse, with a small tapering central lobe in front, 

 produced between the hinder part of the palatine bones. The basi- 

 occipital about as broad as long, rather lozenge-shaped, the front 

 edge being rather arched, not so broad as the basisphenoid. 



a. Front lobe of the sternum broad, with a subcircular outline, as 

 broad as, or broader than, the hinder lobe. 



1. Elseya latisternum. (Plate XXIX.) B.M. 



Front of the sternum broad, much broader on the hinder part, with 

 a rounded outline ; nuchal plate none ; intermediate plate moderate. 



Elseya latisternum, Gray, Ann. & Mag. Nat. Hist. 1871, viii. 

 p. 292. 



Var. 1 . Underside of the shell pale yellow, rather darker on the 

 margin of the shields. There are two specimens of this variety in 

 the British Museum, from Cape York, North Australia, which were 

 described in the 'Ann. & Mag. Nat. Hist.' for July 1867. 



One of these specimens is peculiar for having a small linear extra 

 shield on each side, on the outer part of the abdominal shield, which 

 is unusually short in this specimen. To judge by the thickness and 

 size of the tail, the two specimens appear to belong to two different 

 species. 



Var. 2. This differs in the sternum being pale greyish white, more 

 or less marbled with dark brown. Two specimens of this variety 

 were received from Mr. Krefft, who obtained them in the Burnett 

 River, Queensland. They are exceedingly like the single specimen 

 of Euchelymys spinosa in the British Museum ; but they both have 

 no indication of the narrow nuchal shield observed in that specimen. 

 These are the specimens described in the ' Ann. & Mag. Nat. Hist.' 

 1871, vol. viii. p. 292. 



Var. 3. The underside dark, blackish ; the lower margin reddish, 

 with black edges to the shields. There are two specimens of this 

 variety received from Mr. Krefft. One is the largest example of the 

 species that I have seen. The dorsal shields are rather rugose, with 

 regular linear pits and more elongated grooves. The dorsal line is 

 sunken. The head is covered with a uniform hard shield, which 

 is slightly sinuate on each side of the hinder margin. With this 

 specimen was received another, about two-thirds the size (indeed 

 rather more convex than the other species of the genus in the 

 Museum), which is peculiar for having thirteen marginal shields 

 on each side, six forming part of the margin of the last vertebral 

 plate (see Plate XXIX., animal) ; there is no doubt that this arises 

 from the division into halves of the usual caudal shield ; but they 



