374 Messrs. Hancock & Atthey on the Occurrence of 



XLIII. — On the Occurrence of Loxomma Allmanni in the 

 North iimherhnd Coal-feld. By ALBANY HanCOCK, F.L.S., 



and Thomas Atthey. 



A FEW months ago we announced the occurrence in the Coal- 

 shale near Newcastle of a considerable portion of the cranium 

 oi Anthracosaurus. We have now the pleasure of recording 

 the presence of another large Labyrinthodont Amphibian in 

 the same locality, Mr. Atthey having recently obtained, in the 

 black shale at Newsham, a nearly perfect skull of Loxomma 

 AUmanni, Huxley, which we believe to be the tirst authenti- 

 cated specimen of this fine Labyrinthodont that has been found 

 in this neighbourhood. 



The skull is complete, with the exception of the muzzle, 

 which is entirely wanting ; but in other respects it is in an 

 excellent state of preservation. The exposed surface, which 

 is that of the crown, is wholly covered with the honeycomb- 

 like sculpture usual in these animals. The pits and ridges 

 are remarkably regular and deep, tliough they are occasion- 

 ally elongated ; the ridges are smooth, and have a semigloss, — 

 •which two characters, taken together with the colour, a dark 

 brown, give to the whole surface the appearance of carved 

 box-wood. 



As presented to view, the contom- of the skull is triangular, 

 with the apex truncated and the base or occipital region 

 arched considerably inwards. The apex or muzzle not being 

 present, it is impossible to say how much it was produced 

 when perfect; but, judging from the gentle inclination of the 

 side margins, it would seem to have been much jirolonged. 

 The whole of the muzzle is broken away as far backward as 

 the anterior border of the enormous orbits. Across the broken 

 extremity the skull measm-es about five inches; and the width 

 of the occipital region at the widest part is nine inches ; the 

 length, from the broken anterior extremity to a line drawn 

 between the points of the lateral expansions, is eight inches 

 and a half. But if we make allowance for what is wanting of 

 the muzzle, the length of the skull may be estimated as up- 

 wards of twelve inches. 



The longitudinal centre of the cranium is composed of a 

 comparatively narrow stri]) of bone, which is apparently made 

 up of the frontals, the prefrontals, the parietals, the post- 

 frontals, the ejjiotics, and the occipitals ; but it is quite impos- 

 sible to detennine the boundaries of these component parts, as 

 the sutures are invisible, notwithstanding the fine condition of 

 the specimen. Tlie anterior portion of this compound strip of 

 bone divides the large oblique orbits, the posterior portion the 



