PLESIOCHELYID^E. 197 



long and narrow, 8 in number, and connected with the first of the 

 three suprapygals ; entoplastral wide and generally rounded pos- 

 teriorly ; hypoplastrals relatively long. Vertebral shields of medium 

 width, usually with the underlying areas fluted ; intergular divided ; 

 inframarginals narrow and, as a rule, not extending on to the mar- 

 ginal bones ; sulcus between abdominal and femoral shields ascend- 

 ing towards the hyoplastral suture, and terminating in the middle 

 of the inguinal notch. The width of the vertebral shields is usually 

 equal to about twice their length, but it may be less. The shell is 

 relatively thick, and may or may not have a persistent plastral 

 vacuity. In the adult, according to Eiitimeyer, the carapace is 

 considerably vaulted ; and in specimens which he regards as belong- 

 ing to male individuals it has a tendency to a cordiform shape. 

 The plastral bridge is long, and usually extends from the 3rd to the 

 7th costal. 



As was first pointed out by Eiitimeyer l , and subsequently more 

 fully by Portis 2 , some of the Chelonians from the Kimeridgian of 

 Hanover, described by Maack under the preoccupied name of Stylemys, 

 are referable to the present genus. The type of the genus Clielo- 

 nides, Maack 3 (also preoccupied), of the same deposits, is a young 

 shell, said to have been associated with a cranium 4 . In the cara- 

 pace the vertebral shields are relatively wider than in young indi- 

 viduals of Plesiochelys, but the number of neurals is unknown. In 

 an adult carapace, figured by Portis 5 under the same name (Chelo- 

 nicles .wittei), the vertebral shields (more especially the 4th) are 

 somewhat wider than in PlesiocJielys, and the 8th costals meet in 

 the middle line, as in JTylceochelys. Whether this form should con- 

 stitute the type of a genus must for the present remain undecided. 



Plesiochelys solodurensis, Eutimeyer*. 



The type species. Carapace elongated and ovoid, vaulted in the 

 male ; neural bones elongated ; vertebral shields relatively wide, 

 extending about halfway across the costal bones, with the under- 

 lying areas fluted. Plastron long and narrow, fully ossified, with 

 the sulcus dividing the abdominal and femoral shields ascending in 

 an angular form on to the hypoplastrals ; the postinguinal lobe long, 

 and the anal shields extending on to the hypoplastrals. 



1 N. Denkschr. schw. Ges. Nat. vol. xxv. art. 2, pp. 140-142. 



2 Palasontographica, vol. xxv. art. 3, p. 131 et seq. ^1878). 



3 Ibid. vol. xviii. p. 316(1869). — Preoccupied inl834 for a genus of Lepidoptera. 



4 These specimens are figured by Portis, op. cit. pi. xvii. 



5 Op. cit. pi. xviii. fig. 1. 



N. Denkschr. schw .-Ges. Nat. vol. xxv. art. 2, p. 29 (1873). 



