340 Dr. J. E. Gray on a Fossil Hydraspide. 



of the Royal Asiatic Society' for July 1853. Mr. Carter calls 

 the species Testudo Leithii. He examined the remains of 

 nine specimens, and gives a very good restored figure of the 

 up])er and under surfaces of the head, carapace, and feet of the 

 animal. Mr. Carter, though he refers the species to the genus 

 Testudo, properly refers the fossil to the " Pleuroderal Elo- 

 dians " of Dumdril and Bibron, and especially compares it to 

 the genus Steryiothcerus. He truly observes that no species 

 of this family has been found in the recent state in Asia. 

 All the specimens are, I believe, left in the Museum of the 

 Asiatic Society of Bombay. 



The description and figure of the carapace induce me to 

 believe that the fossil is most nearly allied to some of our 

 existing South- American species of the restricted genus Hy- 

 draspis ; and the remains of the head, which are unfortunately 

 imperfect, lead to the same conclusion : but at present that 

 genus is only found in tropical America. 



The genera of this group of tortoises may be artificially 

 arranged by the sternal plates, thus : — 



1. Sterno-costal symphysis covered by the outer ends of the 



pectoral and abdominal shields. 



A. Pectoral plates very large and long. Abdominal plates 

 short and transverse. HydhomedUSA*. 



B. Pectoral plates four-sided, moderate, subequal. Hy- 

 DRASPis, Chelymys, and Euciielemys. 



C. Pectoral plates triangular. Pelomedusa. 



2. Symphysis covered by the ends of the abdominal plates. 



Pectoral plates narrow, triangular. Sterxoth.ERUS. 



This fossil, according to this artificial table, would be ranged 

 witli Uydrnspis ; and it is peculiar among the Hydrasjyides 

 for the large size of the iutergular plate, the very small 

 triangular gular plates, and the small size and triangular 

 form of the postgular, the pectoral plates being rather longer 

 than the abdominal ones. It is also peculiar for the under- 

 side of the marginal plate opposite the suture between the 

 pectoral and abdominal plates being rather broader than tlie 

 rest, and angular on the inner edge, which T have not seen in 

 any of the recent species. I propose to name it provisionally 

 Hydraspis Leithii, = Testudo Leithii, Carter, Journ. Bombay- 

 Branch of the Royal Asiatic Society, 1853, p. 1, tab. x. & xi. 



It must not be confounded with the Testudo Leithii, 

 Giinther, which is a tme land-tortoise, very nearly allied to 

 T. marjinata of Europe. 



• Sonio specinion?, perlinps males, of JIyilromcdu,<a Maximilionn have 

 the middle of the hindor part of the ^teiiimn deeply conii-nlly concave, 

 while tho front part of ihi^icrnum i> (juite tint. 



