MR. R. LYDEKKER OX ORNITHOSAURIAN REMAINS. 429 



24. On ORNirnosATRiAN KEMAiNs/ro;« the Oxford Clay of Hunting- 

 donshire *. Ey K. Lydekker, Esq., B.A., F.G.S. (Head April 

 16, 1890.) 



My friend Mr. Thomas Jesson recently forwarded to me a few 

 small associated bones obtained from the Oxtord Clay of St. Ives, 

 Huntingdonshire, Avhich are of a certain amount of interest as being 

 the only specimens referable to a Pterodactyle hitherto described from 

 these deposits in England, or, indeed, so far as I am aware, in any 

 other part of Europe. The specimens comprise seven vertehrie, 

 portions of the ilia and ischia of both sides ; one femur and the 

 distal portion of the corresponding bone of the opposite side ; part 

 of a bone, probably from the shaft of the tibia ; and two un- 

 determined fragments. When they came into my hands they wei"e 

 partially bedded in their native clay, and their broken surfaces show 

 the pyritous impregnation so characteristic of Oxfordian specimens. 



The Ornithosaurian nature of the s[)ecimcns is at once sliown by 

 the hollow shafts of the long bones and the structure of the vertebrae, 

 the latter having procoelous centra, with complete obliteration of the 

 neuro-central suture. The two fragmcmts of the femur (fig. 3), which 

 I have placed in apposition, do not exactly fit together, so that there 

 may be a portion missing from the middle of the shaft, and it is 

 quite possible that 1 have not put the proper distal half in apposition 

 with the proximal one. The bones indicate an individual of some- 

 Avhat smaller size than the examjdes of the Lower-Kimeridgian 

 Jihamphorhipichus Geniminc/i figured by Professor von Zittel in the 

 ' Pahcontographica,' vol. xxix. i)\. xii. 



The portions of the pelvis (fig. 4) now remaining are of the 

 peculiar type characteristic of lilKimpliorhijnchu!^, as is so well dis- 

 played in the specimen represented in fig. "2 of the plate cited. The 

 peculiarity of tins type of pelvis is that the ischium is connected with 

 the hinder portion of the ilium to foi-ni a large expanded plate ; 

 while the ilium itself is united with the sacrum by means of four broad 

 andfiattened sacral ribs, which are anchylosed to the ilium, of which 

 they appear to be mere processes. On the other hand, so far as I 

 can gather from Meyer's figure of P. spedahilis^ the pelvis of Ptcro- 

 dacti/his is constituted on quite a different plan ; which alone 

 justifies our regarding the two genera as referable to separate 

 families. ISTow, although the conjoint ilia and ischia of the Oxfordian 

 Pterodactyle are far from ])erfect, yet such of the several processes 

 of the ilia as remain so exactly accord with those of JllKdnplio- 

 rhj/iichus that I think the English form may be safely referred 

 to that genus. 



Of the vertebnc we have two, in apposition, whicli from tlieir 



* When the paper was read the author was under the inqirossiiou that the 

 specimens came Irom Is'onhampton. 



