﻿346 ME. E. THUELOW LEEDS ON" METBIOBHYjSCHUS [Aug. I908,. 



cation as faulty, and in restoring the genus to its original position 

 in Deslongchamps's table. 



The type-specimen, according to Deslongchamps, was found in 

 the zone of Ammonites cordatiis, that is, English Upper Oxfordian. 

 Prof. Bigot writes to me that it came from Callovian strata (Conti- 

 nental division). He remarks : — 



* II ne peut y ayoir de doute a cet egard : on ne sait pas exactement dans 

 quel Ht des carrieres du Mesnil de Bavent ; mais les exploitations d'argile de 

 cette region sent dans les couches a BeinecJcia ancejps, Kepplerites Gowerianus 

 et Froplanulites Kcenigi ' 



The above-mentioned ammonites are characteristic of Lower 

 Oxfordian strata in England. 



Two skulls of MetriorTiynchus, of a species previously unknown to 

 him, have recently been obtained by my father, Mr. A. N. Leeds,. 

 P.G.S., from the Saurian zone of the Lower Oxford Clay, in the 

 neighbourhood of Dogsthorpe, Peterborough. Unfortunately, no 

 other parts of the skeleton were found with them, even the man- 

 dibles being missing. The skulls were discovered (curiously enough) 

 at different levels, about the same time, but undoubtedly belong to 

 the same species. After careful examination and comparison of 

 the two skulls with the description and figure of the type-specimen 

 published in the * Notes Paleontologiques,' and with photographs of 

 it kindly sent to me by Prof. Bigot, I have come to the conclusion 

 that they are to be identified with M. hrachyrliynchus. As I believe 

 that this is the first recorded occurrence of this species in English 

 strata, and as the skulls help to throw additional light on the cranial 

 osteology of M. hrachyrhynchus, especially in the parts which are 

 wanting in the type-specimen, I propose to give some account 

 of them, in the hope that it may amplify Deslongchamps's lucid 

 description. 



The skulls are exceedingly massive throughout, all the bones 

 being thick and strong ; in this respect they compare very favour- 

 ably with the slender, slightly-built cranium of M. super ciliosus. 

 They are neither of them quite perfect, but most fortunately the 

 one supplements the other, although both are perfect in one of the 

 most interesting parts, namely, the frontal region, and the part from 

 the nasals to the prsemaxillse. The first skull, to which I shall 

 refer as iN'o. 164 (Leeds Catalogue), lacks the anterior portion of 

 one prsemaxilla and some parts of the back of the skull. In the 

 second skull, No. 165 (Leeds Catalogue), the anterior portion of the 

 prsemaxillae is entirely absent, also the articular portion of one 

 quadrate ; but, on the other hand, the posterior part of the pala- 

 tines is very well preserved, taking into account the crushing which 

 all skulls from the Oxford Clay of the Peterborough district undergo, 

 and the postf rentals laterally viewed have almost preserved their 

 natural contour. 



