214 



FOSSIL TURTLES OF NORTH AMERICA. 



peripheral bones; but he also expresc doubt whether these bones might not rather belong 

 to the rear of the carapace. Among the bones in the lot mentioned there is none that can be 

 recognized as a bone belonging in the midline. Fragments are found which, when fitted 

 together, furnish fig. 271. The bone markt by I is certainly that called by Cope the first 

 marginal. It seems impossible to determine just where it belonged. It is, for various reasons, 

 improbable that it belonged in front. Hence, assuming that Cope had a symmetrical bone 

 which joined the supposed first peripheral, the latter is here taken to belong behind and to 

 be the last left peripheral. 



Cope estimated the length of the bone I to be 153 mm. It is not known whether he took 

 account of the narrow fragment on the right of the figure; but there is no doubt that this 



fragment belongs where it is placed. 

 The length of the bone then, not includ- 

 ing a deeper plate on the right that 

 would be hidden when the bone joined 

 the one next to it, is 165 mm. The 

 greatest width, omitting a deep sutural 

 plate, is 100 mm. The thickness on the 

 right side is 27 mm. The greatest thick- 

 ness is to the left of the middle of the 

 length and is 45 mm. Cope states that 

 this is the thickness nearthesutureof the 

 second peripheral; from which expres- 

 sion we may infer that the narrow frag- 

 ment on the left of the figure, markt 2, 

 is a part of the penultimate peripheral. 

 The free border of the bone I, so far as 

 represented, is thick and obtuse. Fig. 

 271 gives a section from a to b. The free 

 border of this bone, on the left, projected 

 in an obtuse angle. It appears improb- 

 able that such an irregular border 



Fig. 271. Lembonax insularis. Fragments of two bones 

 of the carapace, with section of one. Type. Xj. 



a to by direction of section. I, probable last peripheral; 

 2, probable penultimate peripheral. 



would be found on~the front of the carapace. The upper surface is convex and undulating, 

 but there is no definite sculpture. Toward the free border the surface is pitted and rough. 



Seen from below the bone is concave. Near the hinder border of the narrow fragment on 

 the right is a prominent ridge. A suspicion is awakened that this is the fragment which Cope 

 mentions as bearing the support of a vertebra. The ridge mentioned continues for some 

 distance on the larger part of the bone of which the fragment is a part. Behind it, on the 

 larger fragment, are two equally prominent ridges, followed by some smaller ones, and these 

 are separated by deep grooves. What is the meaning of these grooves and ridges can not be 

 determined. It is possible that the median bone, whether nuchal or pygal, sent a process 

 along the under surface of the bone 1, two-thirds its length. 



The bone shown on the left of the one indicated by I has a thickness of 33 mm.; and it 

 is possible that this is a part of what Cope called the nuchal. In that case the bone 1 would 

 be either the right ultimate peripheral, or first left peripheral. 



As in the case of L.P propylceus, it is impossible to state with certainty that this species 

 belongs to the genus Lembonax. 



Lembonax? propylaeus Cope. 



Fig. 272. 



Lembonax propyhcus, Cope, Proc. Acad. Nat. Sci., Phila. 1872, p. 15. 

 Lembonax prophyhcus, Hay, Bibliog. and Cat. Koss. Vert. N. A., 1902, p. 444. 



I he type of this species is now in the American Museum of Natural History, and has 

 received the number 13 10. This specimen was found in the Eocene greensand, in the vicinity 

 of Farmingdale, Monmouth County, New Jersey, the same formation and locality that furnisht 

 the type of the genus, L. polemicus. 



