84 Dr. J. E. Gray on Trionyx Phayrei. 



for 1868 (vol. x. p. 18), named after him a species of Trionyx, 

 thus : — 



" Trionyx Phayrei, Theobald. 



*' Capite typico, facial! forma forsan rotundiore. Sterni sculptura 

 modica, sive retictdationibus minoribus quam in T. gangetico. 

 Sculptura ad latus regidariter reticulata, sed vertebrali regione 

 post secundas costas parum dilatata sive incrassata. Thorace 

 valde cartilagineo, vix ullis (praeter ad latus) tuberculis osseis 

 armato. Colore supra olivaceo, lineis fuscis eleganter marmo- 

 rato, subter flavescente pallido. 



" Habitat in fluminibus montium Arakanensium, prope Bassein." 



The Latin appears to be a translation of the following ob- 

 servations : — 



" Granulation of sternum not very coarse, less so than in 

 T. gangeticus, on the sides regular, but coarser and larger 

 along the centre of the back behind the second pair of ribs. 

 Thorax highly cartilaginous, and almost devoid of bony callo- 

 sities save at the margin, where the granulations are slightly 

 developed. Colour during life dark dull brown, handsomely 

 lined, as in Giinther's figure, I. c. ; below yellowish white. 

 Captured in a hill-stream on the Arakan hills in the Bassein 

 district." 



It is curious that in both these descriptions Mr. Theobald 

 has mistaken the thorax for the sternum, and the sternum for 

 the thorax ; unless this is so, these descriptions are not intelli- 

 gible or consistent with the following observations : — 



" This is a somewhat aberrant species in some respects, and 

 was at first confounded by me with Chitra indica of Giinther's 

 Monograph, from the precise resemblance which the marbling 

 of the upper part bore to that figure. Since, however, examin- 

 ing the specimens in the British Museum, I find that the ani- 

 mals are very difierent. The true Chitra of Gray (Proc. 

 Zool. Soc. Feb. 23, 1864, p. 17) does not, to my knowledge, 

 occur in Birma. The Chitra indica figured in Giinther's 

 monograph is, on the authority of Dr. Gray, his Pelochelys 

 Cantori. The skull of the present species cannot readily be 

 distinguished from that of T. gangeticus, though to my 

 view it seems more arched, and rounded in profile. The 

 thorax resembles that of T. gangeticus ; but the sternum pre- 

 sents a remarhable difference in the development of the hony 

 plates, and more nearly, in general characters, approaches 

 to Dogania subplana, Oray. The osseous tuhercidar surface, 

 however, is less developed and more feebly sculptured (the age 

 and size of the specimen considered) than in any of its allies, 

 and at a glance serves to discriminate the present species from 

 them. 



