AND NORTHUMBERLAND COAL MEASURES. 235 
the large tooth shows indications of having been occupied by 
others which have been displaced. The large laniary is conical, 
rather compressed laterally, not very sharply pointed,* reflexed 
until near the extremity when it is directed straight upwards ; 
it is ornamented on the sides and behind with distant, raised, 
longitudinal strie or delicate ribs, from the base to near the 
point; about the point and in front it is smooth. The other 
teeth resemble this in general character, but are not so strongly 
reflexed, rather more sharply pointed and rounder. 
Localities—The teeth of this species have occurred to us at 
Newsham, and at Monkwearmouth in black stone from the roof 
of the Hutton (?) seam. 
3. Honoprycuivs, sp. indet. Pl. VI., Fig. 4. 
Fig. 6 represents an imperfect mandibular bone, armed with 
conical teeth, apparently belonging to a small Holoptychius. The 
articular extremity is wanting; the rest of the bone up to its 
junction with the opposite ramus is complete. It is ths. of an 
inch in length, and 3th. or less in height. A large conical, 
reflexed tooth is placed near to the extremity, with a small one 
immediately in front. Behind the large tooth are two others of 
about half the size; then follow six smaller teeth only one- 
fourth the size of the largest. All the teeth except the largest 
are smooth, but slightly reflexed, and appear to be arranged in 
pairs. The large tooth is covered on the sides and behind with 
rather coarse, inosculating, longitudinal strie. The external 
surface of the bone is covered with a sort of rugose ornamenta- 
tion which towards the extremity becomes more tuberculous in 
character. 
Locality —Newsham. 
EXPLANATION OF PLATE VI. 
Fig. 1 RKhizodus lanciformis, interior of fragment of mandible. 
rs external view of same. 
3 a tooth twice natural size, 
4 Holoptychius, sp. indet. ramus of mandible. 
5 Holoptychius sauroides, portion of mandible, internal aspect. 
7” tooth natural size. 
* The enlarged view of the tooth of this species, given in the Plate (Fig. 6), represents 
it rather too bluntly pointed. 
2D 
