180 REPORT— 1841. 



above enumerated ; and again, tlie affinities to the freshwater forms whieli 

 the skeleton of some of the Eocene Clcelones exhibit, accord with the indi- 

 cations tiiat tiicy inhabited the estuary of a great river. 



Order OPHIDIA. 



In the Appendix to the second 4to edition of the ' Ossemens Fossiles,' Cu- 

 vier remarks, " Les os de serpens sent encore phis rares, s'il est possible. Je 

 n'en ai vu que des vertebres des breches osseuses de Cette, dont j'ai parle tl 

 Tarticle de ces breches, et une seule des terrains d'eau douce de I'ile de Shep- 

 pey*." 



The'Ophidiolites from this formation have been the subject of a memoir 

 by me, pubUshed in the sixth volume (second series) of the Geological Trans- 

 actions, in which the best-preserved specimens in the collections of John 

 Hunter and Mr. Bowerbank are described. The Hunterian Ophidiolites 

 were referred by the Founder of the collection, in the original MS. Cata- 

 logue, to the Crocodile ; some of those in the private collections I found 

 ticketed •' Vertebrae of Tortoise." All these specimens presented the general 

 characteristics of the vertebrae of serpents, and resembled in structure as well 

 as size those of the Constrictors (Python and Boa^ more than those of the 

 colubrine or poisonous families. Very recognizable differences are to be dis- 

 cerned in the Eocene fossil vertebrae as compared with the vertebrae of exist- 

 ing Pythons and Boae ; they are longer as compared with their height or 

 breadth ; the costal tubercle is placed lower down ; the transverse process 

 supporting the lower anterior articular process has a greater vertical extent^ 

 and the ridge continued from the lower anterior to the lower posterior oblique 

 ■process is less developed ; the oblique processes do not extend so far outwards, 

 and the spinous process is higher, but has a less antero-posterior extent than 

 in existing land-serpents. The middle of the posterior margin of the neura- 

 pophysis, opposite the external angle of the articular excavation or mortise, 

 is produced backwards in the form of an angular plate. The inferior surface 

 of the vertebra is not longitudinally carinated, as in some Coluhri, but has a 

 tubercle at the middle of the anterior part, as in the Python. 



These differences justify the consideration of the Sheppey Ophidiolite as 

 the representative of a distinct genus as well as species, for which I have pro- 

 posed the name of Palceophis toliapiciis. 



The largest of the Ophidiolites in Mr. Bowerbank's collection exhibits a 

 portion of the vertebral column suddenly bent upon itself, including about 

 thirty vertebrte, and indicating the usual lateral flexibility of the spine. The 

 Hunterian specimen also consists of a group of as many vertebras more dis- 

 jointed, and cemented, with a number of long and slender ribs, irregularly 

 together by a mass of indurated clay. In the ■museum of Mr. SauU a few 

 vertebrae, and a fragment of the skull of the same Palaoplds, likewise from 

 Sheppey, are preserved. The size of the vertebrae in the foregoing speci- 

 mens corresponds with that of the vertebrae of a boa constrictor of 10 or 

 12 feet in length. 



Vertebrae of a serpent agreeing in character with those of the London 

 clay at Sheppey, but smaller, have been obtained by Mr. Colchester, from 

 the sand of the Eocene formation underlying the Red Crag at Kyson or 

 Kingston in Suffolk. These have also the small tubercle at the under and 

 back part of the body of the vertebra, instead of the ridge, as in Coluber and 

 Naja ; and thus, like the larger vertebrae from Sheppey, they come nearer to 

 the Python ; but the bodies of these vertebra; are longer in proportion to 

 their breadth, as in the Sheppey PalwopMs. The tubercle for the rib is 



* Tom. V. part ii. p. 526. 



I 



