BEITISH ASSOCIATION MEETING AT NEWCASTLE. 



393 



to be a Discina. In the shale it is always more or less scattered, but in 

 the ironstone it is so abundant in certain zones as to cover the whole of 

 the surface. Associated with this fossil, both in the shale and the iron- 

 stone, are specimens of Beyrichia arcuata, and in the ironstone alone a 

 few obscure vegetable remains. 



About 100 fathoms below the horizon of the preceding fossils another 

 zone of fish-remains occurs, and in the intermediate space more than one 

 band of Anthracosia and Anthracomya. The stratum that chiefly yielded 

 the fish-remains was passed through in sinking the Hyhope Colliery, near 

 Sunderland, and it consists of highly-carbonaceous black shale with inter- 

 calations of coal, or, as the miners term it, " blackstone and coal-pipes 

 mixed." Immediately over it is a 3-inch seam of splint-coal. From this 

 bed the authors have taken the finely-enamelled scales of Megalichthys 

 Hibbcrti, and others usually referred to Holoptychius, as well as such as 

 evidently belong to species of Palseoniscus or Amblypterus ; also sauroid 

 teeth of various sizes, the larger of which appear to belong to Megalichthys 

 or Ehizodus, and the teeth of Diplodus gibbosus. Along with these oc- 

 curred various detached bones and coprolites ; and on one horizon great 

 numbers of Anthracomya were associated, and with them two species of 

 Entomostraca, — Cytherojpsis Scotoburdigalensis and a form yet undescribed. 

 Remains of plants, too, were not uncommon in this bed. Immediately 

 overlying the splint-coal is another stratum of black shale, 4 feet 2 inches 

 thick, and this is overlaid by grey shale to the thickness of 36 feet. In 

 these beds the remains of fish were also found rarely, and wnth them, to- 

 wards their base, were also met with specimens of Lingula myiiloides 

 (Syn. Credneri), examples of which we believe we also got from the black- 

 stone underlying the splint-coal. 



The next horizon at which the remains of fish have been noticed is about 

 120 fathoms below the one just mentioned, in a thin bed of black shale or 

 " stone " that rests on the top of the Low Main Coal, at Newsham, about 

 10 miles north-east of Newcastle. The remains would appear to be far 

 more abundant on this horizon than on any hitherto discovered ; and there 

 has been obtained from the black shale that marks it, one of the finest 

 series of carboniferous fish-remains that perhaps exist in the north of 

 England. These fossils consist of scales, spines, jaws, teeth, and bones, 

 the most important of which we notice below. Amongst the most in- 

 teresting are some large spines of Placoideans. The most common of these 

 is the G-yracantJms tuberculatus, of Agassiz. Perfect examples of this 

 spine measure 15^ inches in length and 6-| inches in circumference. It is 

 a notable feature in them that they are nearly always much worn at the 

 point, as though they had been subjected to considerable wear and tear. 

 It should also be observed that all these spines are a little out of true 

 symmetry ; that is, they are slightly bent to one side. The lateral deflec- 

 tion, moreover, is not always in one direction in different spines, but some- 

 times to the right and sometimes to the left. It has hence been suggested 

 by Mr. Albany Hancock that the spines may not have been dorsal ones, 

 as usually supposed, but paired spines, that were probably placed in front 

 of the pectoral fins. Specimens of another spine have occurred, somewhat 

 resembling G. tuberculosus, but differing from that species in having the 

 concave border denticulated and bounded on each side by a plain or un- 

 tuberculated area, as well as in being of smaller size. The authors have 

 also found specimens of a large spine that appears to be identical with the 

 G. formosus of Agassiz. Also examples of an Orthacanthus, about 12 

 inches long, and of a Pleurocanthus, 9 inches in length, and of another 

 that seems referable to Leptacanthus. Besides these, there have been 



YOL. VI. 3 E 



