700 



PROP. H. Gr. SEELEY ON THE EEPTILE 



Other Species of Emys. 



Another species, represented by the remains of more than one 

 example, is, however, known chiefly from the hypoplastral plates. 

 It appears to have been a smaller species than the last, though it is 

 not easy to estimate its size from the distance between the axilla?, 

 or from the breadth of the abdominal scutes. The hypoplas- 

 tron shows some indication of the median and anterior sutural 

 margins, which would indicate a broad species, after the pattern of 

 the foregoing. The length of the fragment is 6| centim., and its 

 breadth about 6 centim. The transverse scutal impression is from 



to 3 centim. behind the anterior suture. The bone is compressed 

 to a sharp margin, which is prolonged as an elevated ridge for about 

 1 centim. beyond the inguinal notch. The margin is nearly straight. 

 I regard this ridge as indicative of a well-marked species. 



A third species is distinguished by the way in which the axillary 

 and inguinal processes are obliquely overlapped. A fourth species, 

 of small size, is represented by many parts of the carapace and 

 plastron. 



Ar^osatjrtts gracilis, Seeley. 

 Vertebra. 



The vertebra of a lizard, figured by Biinzel, pi. vi. fig. 11, is very 

 imperfect, and so badly drawn as to give no just idea of its cha- 

 racters. It is remarkable for the perfectly globular form of the 

 posterior articular ball, which is nearly 6 millim. in transverse 

 measurement, and nearly 5 in vertical measurement. It is margined 

 by an impressed groove, which extends further forward on the 

 neural margin than on the visceral margin. The length of the cen- 

 trum in the middle line is 13 millim. What remains of the an- 

 terior cup is deeply excavated to correspond with the articular 

 ball, with a sharp margin conspicuous on the inferior border. The 

 inferior interarticular surface of the centrum is 1 centim. long ; on 

 its base run two parallel blunt ridges, divided by a median groove ; 

 external to these ridges are two oblique impressed concave lateral 

 areas, which are broad in front and narrow behind, margined 

 superiorly by an oblique rounded ridge, which ascends from the 

 upper margin of the articular ball towards the middle of the arti- 

 culation for the rib on the anterior part of the vertebra. This arti- 

 culation for the rib is a strong process, extending laterally further 

 than the width of the articular cup of the centrum, is concave from 

 above downwards in front, looking obliquely downward and out- 

 ward, long and narrow, rounded from fore to back, and most 

 elevated proximally. It carries superiorly the prsezygapophysis, 

 which was a large oval surface, looking upwards and a little inwards, 

 placed just above the articulation for the rib, and considerably above 

 the intervertebral articulation. The zygapophysis is only preserved 

 on the left side, the portion which had existed on the right side 



