206 MESSRS. HANCOCK AND ATTHEY ON THE 



the exposed portion is three-quarters of an inch in length ; it is 

 half an inch wide at the base, and is three-eighths of an inch 

 wide at the upper extremity ; it is therefore probable that not 

 half the tooth is seen, and that it cannot have been less than an 

 inch and a half in length. 



The under surface of the specimen is partially exposed ; but 

 too little is displayed, and that little is too much disturbed to ad- 

 mit of clear elucidation. Part, however, of the basi-sphenoid and 

 its lateral processes can be observed, as well as a portion of the 

 palatal bones ; also the palato-temporal foramen seems to be in 

 part recognizable. 



We have already stated that this fine cranium is the first au- 

 thenticated evidence of the occurrence of Loxomma in the shale 

 of the Northumberland coal-field. Mr. Atthey, however, has 

 had in his cabinet for several years the crushed cranial bones of 

 this Labyrinthodont ; but, owing to the confusion of the parts, 

 we were quite unable to determine to which of the known forms 

 to refer them, until the possession of the specimen under discus- 

 sion cleared up the matter. We can now trace distinctly the 

 presence of the central portion of the cranium, which agrees 

 with that of the specimen before us in form and surface-sculp- 

 ture. A portion of a maxilla, with a few teeth attached, as well 

 as considerable remains of the lateral expansions, are likewise 

 determinable. 



Having now the advantage afforded by the possession of this 

 almost perfect skull of Loxomma Allmanni, we are also enabled 

 confidently to refer to the two magnificent Labyrinthodont skulls 

 exhibited and described, under the name of Pteropla-x brevicornis, 

 by Mr. James Thomson and Prof. Young, of Glasgow, at the 

 meeting of the British Association held last year at Exeter. On 

 passing through Newcastle on his road homewards, Mr. Thomson 

 kindly gave us an opportunity of inspecting these specimens, and 

 at the time we pronounced them to belong to Loxomma — cer- 

 tainly not to Pteroplax. We are now in a position to speak on 

 the subject without the least hesitation, in confirmation of our 

 opinion then expressed. That our cranium is that of Loxomma 

 there is not the least doubt ; that it agrees with Mr. Thomson's 



