V LABYKINTHOnONT SKULL lUOM THE KILKENNY COAL-MEA.SXJRES. 343 



11). On a Lauykinthodoxt Skull fro}a the Kilkenny Coal- 

 MEAsuKES. By K. Lydekker, Esq., B.A., F.G.S. (Read Feb- 

 ruary 25, 18<)1.) 



In goiug through the collection of Labyrinthodont remains from 

 the Coal-measures of Jarrow Colliery, Co. Kilkenny, preserved in 

 the Science and Art Museum, Dublin, I noticed a fragment of shale 

 showing the lower jaw of a Labyrinthodont, which appeared to in- 

 dicate a species different from any of those hitherto described from 

 these beds. The slab in which the specimen is contained is of a 

 slaty nature, without any of the pyritous matter which is so fre- 

 quently fatal to the permanent preservation of the Jarrow fossils. 

 On examination it appeared that by splitting the fragment the 

 upper surface of the skull might also be revealed : and this opera- 

 tion fortunately proved successful. Whereas, however, the external 

 sculptured layer of the bones of the lower jaw is exposed, in the case 

 of the cranium the line of fission has traversed a film of shale over- 

 lying the bones, and it has only been practicable to remove this 

 film so as to expose the sculptured surface in the left postorbital 

 region. 



As is the case with all the Jarrow fossils, the specimen has been 

 completely flattened by pressure ; but, although the width of the 

 cranium has been doubtless thus slightly increased, the general 

 contour is fairly well exhibited. The outline of the right side of 

 the cranium is, indeed, in great part destroyed, owing to the re- 

 flection of its maxillary border on to the inferior surface of the 

 slab. On the left side of the cranium the contour is, however, 

 entire. The extremity of the premaxillae, carrying three large 

 conical teeth on the left side, is bent over on to the inferior surface 

 of the slab, and thus overlaps part of the mandibular symphysis. 

 The innermost tooth is se])arated by an interval of about 0*4 inch 

 from the middle line ; and all the teeth pass on the outer side of 

 the mandible. The left mandibular ramus is fairly well preserved, 

 but the opposite one has been much crushed and distorted, and is 

 confused with some of the bones of the right side of the cranium. 



Fig. 1 (see next page) gives the outline of the cranium, the contour 

 of the right side restored from the opposite one. From this figure it 

 will be seen that the skull has a parabolic contour, with a length of 

 nearly four inches and a width of nearly as much. The orbits are 

 large, nearly circular, separated by an interorbital bar wider than 

 their transverse diameter, and situated mainly in the anterior half 

 of the skull. The supra-occipital border forms an expanded and 

 slightly concave line, terminating in small epiotic cornua, which are 

 directed slightly outwardly, and externally to which is a small slit. 

 The larger auditory slits are very deep and narrow. The contour 

 of the left mandibular ramus given in fig. 2 shows a high degree 

 of arcuation, corresponding with the shape of the cranium. 



Compared with the smaller imperfect cranium figured by Prof. 



