PALiEONTOLOGY 



Passing on to the consideration of reptiles from formations older 

 than the Oxford Clay, we find remains of the long-snouted crocodile 

 known as Steneosaurus brevidens occurring not uncommonly in the Great 

 Oolite of the county ; teeth referable to some species of the same 

 genus have been found in the Cornbrash near Peterborough ; while 

 bones and teeth assigned to S. chapmam have been recorded from the 

 Upper Lias of Green's Norton, near Towcester, and those of 6". latifrons 

 from the same formation near Northampton. These and other crocodiles 

 from the Oolitic deposits differ from the existing members of the group 

 in that both the terminal articular faces of their vertebra are concave, 

 instead of alternately convex and concave. From the Great Oolite of 

 Blisworth the British Museum possesses two caudal vertebrae of a dino- 

 saur which has been named Cetiosaurus oxoniensis, but whose proper title 

 is apparently Cardiodon oxoniensis. In the same collection are two other 

 caudal vertebrse from the Forest Marble of Cogenhoe which have been 

 assigned to C. glymptonensis. Teeth of the great carnivorous dinosaur 

 Megalosaurus bucklandi, now in the British Museum, were discovered by 

 Mr. Sharp in the Inferior Oolite of Duston. A vertebra of Ichthyosaurus 

 was obtained so long ago as 1837 from the Upper Lias of Blisworth, 

 while a humerus of the same genus is recorded from the Lias of Bug- 

 brook. The Lower Jurassic strata of Higham Ferrers have also yielded 

 a vertebra of Pliosaurus, and remains of the allied genus I'haumatosaurus 

 occur in the Upper Lias of Kingsthorpe and Crick, as well as in the 

 Marlstone, or Middle Lias, of Bugbrook ; the species from the two 

 last-named localities being Th. propinquus. Plesiosaurian vertebra like- 

 wise occur in the Cornbrash of Rushden. 



Fish remains, at all events in a determinable condition, do not 

 appear to be very abundant in the Lower Oolites of the county. The 

 pavement-toothed sharks (Cestraciontida), now surviving in the form of 

 the Port Jackson species, are represented by palates of Asteracanthus acu- 

 tus and Strophodus magnus from the Cornbrash, and by the last-named 

 species and iS". tenuis from the Great Oolite of the county. Another 

 genus of ganoid fishes, the well-known Lepidotus, with spherical 

 button-like palatal teeth and shining rhomboidal scales, is represented 

 in the Middle Lias of the county by L. elvensis, and in the Great Oolite 

 by L. tuberculatus. A ganoid at present peculiar to the Inferior Oolite 

 of Northamptonshire is Ophiopsis Jiesheri, of which the type specimen 

 was obtained from the railway tunnel near Blisworth. The pycnodont 

 ganoids, which have numerous crushing teeth, frequently showing a 

 sculptured pattern on the palate, are represented in the county by two 

 species of the genus Mesodon {M. ruguhsus and M. bucklandi) from the 

 Great Oolite. 



The invertebrate fossils of the Northamptonshire Oolites were 

 worked out in great detail about thirty years ago by Mr. S. Sharp, and 

 the results published in the Quarterly "Journal of the Geological Society^ for 



' Vols. xxvi. p. 354, and xxix. p. 225. 

 43 



