chelonid^:. 57 



Lytoloma longiceps (Owen 1 ). 



Syn. Chelone longiceps, Owen 2 . 

 Puppigerus longiceps, Cope 3 . 

 Pachyrhynchus longiceps, Dollo 4 . 



The type of Piippigerus ; apparently of small size. 



Skull depressed and much pointed anteriorly, with a long in- 

 terval between the heart-shaped nares and the subcircular orbits, 

 in which the frontal border is notched, and a moderately wide and 

 nearly flat interorbital bar. Pterygoids very deeply emarginate 

 laterally. Both the occipital and interparietal shields long and 

 narrowed anteriorly. Mandible unknown. Carapace broad and 

 depressed, with the antero-lateral surfaces of the neural bones 

 much shorter than the posterior. Vertebral shields in adult of 

 moderate width, which is approximately equal to the length. 



The type skull is figured by Owen in his ' Eeptilia of the London 

 Clay, &c.' vol. i. pt. i. pi. iii., and indicates a half-grown individual, 

 the posterior nares being situated on the line of the anterior border 

 of the temporal fossae. 



Hab. Europe (England). 



All the undermentioned specimens indicate immature individuals. 



38950. The imperfect shell, with the occipital region of the skull 

 (Fig.) in situ; from Sheppey. The carapace is figured by Owen 



in his ' Eeptilia of the London Clay, &c.' pi. v. fig. 1. The 

 posterior neurals are relatively short. With the exception 

 of its anterior extremity the plastron is nearly entire. 

 The basioccipital and pterygoidal region of the cranium 

 agrees precisely with that of the type skull. Some of the 

 bones of the pelvic girdle and limbs are seen in the in- 

 guinal region. Bowerbanh Collection. Purchased, 1865. 



38951. A larger shell, wanting the marginals; from Sheppey. 

 (Fig.) Figured by Owen, op. cit. pi. v. fig. 2, from the plastral 



aspect. The hinder neurals are longer and narrower than 

 in the preceding specimen ; the whole of the bones of the 

 plastron are shown. Boiverbank Collection. 



25608. A smaller shell, wanting the marginals, and some of the 



(Fig.) costals imperfect ; from Sheppey. Figured by Owen in 



his 'History of British Fossil Eeptilia,' Chelonia, pi. v. 



1 Eep. Brit. Assoc, for 1841, p. 177 (1842).— Chelone. 2 Loc. cit. 



3 Trans. Amer. Phil. Soc. vol. xiv. pt. i. p. 235 (1870). 



4 Bull. Mus. R. Hist. Nat. Belg. vol. iv. p. 138 (1886). 



