532 E. Wilson and J. Shipman — The Keuper Basement Beds. 



Several specimens of Lahyrinthodonts, in excellent preservation, 

 Lave been found along with the remains of the fishes. One of them, 

 a new genus of large size, was described and named by Professor 

 Huxley Pholiderpeton scutigerum. 



The Black-bed Coal is in the Lower Coal-measures about 120 feet 

 higher in the series than Elland Flag-rock. Immediately above the 

 Coal there is a bed of shale containing a considerable quantity of 

 Clay-ironstone in nodules, which is worked by the Low Moor Iron 

 Company along with the Coal. The fossil fish and Lahyrinthodonts 

 are from this shale immediately above the Coal. 



Ctenacanthus minor, Davis, sp. nov. (Natural size.) 

 Ctenacanihus minor, mihi. Spine: length, 1-4 inches; greatest 

 breadth, *3 of an inch. The base is imperfect, and the tip of the 

 spine is also wanting. It is slightly curved, is very strong, and has 

 been very deeply implanted in the flesh ; the basal portion constitutes 

 more than half the entire length, and if the specimen had been perfect 

 would have taken up quite two-thirds ; probably a larger proportion 

 than exists in any other species of Ctenacanthus. The lateral faces 

 are compressed anteriorly ; posteriorly they expand and give to a 

 section of the spine a triangular form. Along the back of the spine 

 there is a deep groove, no posterior denticles can be seen. The line 

 dividing the exposed part of the spine from the base forms an angle 

 to the length of the spine of about 45°. The anterior portion is pro- 

 duced so as to form a median keel, whilst on each side there are six 

 or seven well-defined ridges or costa? separated by deep intercostal 

 spaces. The ridges run parallel to the posterior margin for the most 

 part, whilst those near the anterior portion run out towards the 

 point without impinging on the median keel. 



This spine does not appear to be in close relationship with any of 

 Ctenacanths hitherto described. Its short wedge-shaped form in the 

 part exposed, and the extremely large and strong base, serve to dis- 

 tinguish it from all other species of the genus. I suggest the 

 specific name minor as signifying its relatively small size. 



III. — On the Occurrence of the Keuper Basement Beds in 



the Neighbourhood of Nottingham. 



By E. "Wilson, F.G.S., and J. Shipman. 



HITHEBTO, exposures of the junction of the Bunter formation 

 with the Keuper, in the Nottingham district, have shown the 

 brown sandstones and red marls of the " Waterstones," with a band 

 of dolomitic conglomerate at the base, resting directly on an eroded 

 surface of the Bunter Pebble Beds. 1 Recently, however, between 



1 J. Shipman, " Conglomerate at the Base of the Lower Keuper," Geol. Mag. 

 1877, p. 497. 



