450 H. GOVIEE SEELEY ON EMYS HOEDWELLENSIS. 



border is sinuous ; they are entirely in the hyosternal bones. They 

 measure 1| inch in length in the median line ; and each scute is 

 2 \ inches broad ; in the entosternal or interclavicular region the 

 plates are concave. 



The pectoral scutes have subparallel borders ; they are 1 J inch 

 long; and each is 3| inches broad. Their posterior border is 

 entirely in the -hyosternal bones. 



The abdominal scutes are 3 inches in length ; and each is nearly 

 square. Their posterior border is 1^ inch from the hinder border 

 of the hyposternal bones. The femoral plates are imperfectly in- 

 dicated. 



The hyposternal plates are 3| inches long ; and each is 2f inches 

 broad to the femoral notch, and | an inch thick where it joins the 

 xiphisternal bones behind. 



The hyosternal plates measure 4 inches in extreme length from the 

 margins where they join the clavicles to the hyposternal suture ; but 

 they measure only If- inch in the median line. Each is 2j inches 

 broad at the humeral notch, and 3 J inches broad at the lateral 

 suture. 



The interclavicle is 2J inches broad and 1| inch in length. It 

 is rounded in front, and has two straight anterior surfaces for union 

 with the clavicles ; posteriorly the bone is convex ; and this margin 

 is received into a concavity formed by the hyosternal bones. 



In front the clavicles form a concave border 2| inches long ; this 

 border terminates laterally in a sharp angle, behind which the bone 

 extends laterally on each side for If inch. Every scutal area is 

 marked with concentric lines of growth. 



The only Emydian remains from Hordwell hitherto noticed are 

 a few isolated plates figured by Prof. Owen in 1849, in the Palaeon- 

 tographical Society's Monograph of the fossil Tertiary Reptilia 

 (pi. xxiv.), and the hyosternal and the hyposternal bones of a large 

 Chelonian plastron (pi. xxvii.), named Emys crassus. These latter 

 remains are briefly noticed on the last page of the monograph, and 

 are said to be remarkable for their large size and great thickness. 

 The hyosternal bone is in the British Museum. And the hyosternal 

 bone in the species now described differs from it not only in these 

 points, but in the form of the plate, which is more rounded anteriorly, 

 and in the positions of the scutal impressions. 



The most distinctive characters by which this species is separated 

 from all others, recent or fossil, are : — the broad, short, gular scutes 

 with sinuous sutures ; the subtriangular nuchal scute ; the sub- 

 pentagonal first vertebral scute, broader than the succeeding 

 quadrate vertebral scutes ; and the concentric ornamentation left on 

 the carapace and plastron by all the scutes. 



