124 Proceedings of the Royal Physical Society. 



tion of a large mandible is shown, which at its thickest part 

 is no less than l^V inches in depth. A fracture displays, in 

 vertical section, a large incurved conical tooth, whose height 

 above the jaw-margin cannot, however, be accurately deter- 

 mined, as the apex is deficient. The outer surface of the 

 dentary bone is sculptured with closely-set, sinuously-con- 

 torted, and interrupted ridges, passing into tubercles, the 

 sides of which are again ornamented with delicate vertical 

 striae. On the edge of the specimen is also seen a portion, 

 3 inches in length, of the dentary margin of the maxilla, the 

 outer surface of which is closely tuberculated in the same 

 way as the portion of jaw shown in Mr Grossart's specimen 

 from Carluke — the tubercles, sometimes round, sometimes 

 confluent, being again ornamented with exceedingly delicate 

 strise. The maxillary teeth are, except the impression of a 

 small external one, covered up by the intractable matrix; 

 but the bone being broken longitudinally through a little 

 above the dentary margin, the basal pulp cavities of four 

 large laniary teeth are opened into in the space of 1^ inches. 

 The portion of maxillary margin exhibited is 3 inches in 

 length, but it is broken off at both ends, and, judging from 

 its curves and the thickness of the bone itself, it must have 

 originally been considerably longer. 



Mr Stock also possesses a specimen showing the posterior 

 or expanded portion of the maxilla displayed, the outer 

 surface of which is covered by a close tuberculation entirely 

 similar to that above described, and the scales associated 

 with it are sufficient for its identification as belonging to 

 the same fish. Two large laniary teeth, with a few of the 

 more externally placed smaller ones, are visible on the 

 margin. 



A nearly entire head is seen in another of Mr Gibson's 

 specimens, and again in one collected by Mr Peach. In 

 both the cranial bones are much crushed and broken, and 

 their external sculpture not exhibited; but the skull is 

 clearly seen to be constructed on the ordinary Palseoniscid 

 type, with oblique suspensorium, wide extent of gape, etc. 

 In Mr Peach's specimen, which is rather a small one, the 

 left ramus of the mandible is shown in its entirety, and 



