500 A. Smith Woodward—On a Species of Onychodus. 
VI.—Nore on THE OccURRENCE OF A SPECIES OF ONYCHODUS IN THE 
Lower Oup Rep Sanpstone PassaGre Beps or Leppury, HERe- 
FORDSHIRE. 
By A. Smiru Woopwarp, F.GS8., F.Z.8.; 
of the British Museum (Natural History). 
URING a recent visit to the University Museum at Oxford, I 
observed in the Grindrod Collection an interesting small fossil 
apparently adding to the known fauna of the Ledbury Passage Beds 
a remarkable type of fish, hitherto only met with in the Middle and 
Upper Devonian of the United States. Through the kindness of 
Professor Green, I have since had the opportunity of studying this 
specimen in London; and it is shown, of twice the natural size, in 
the accompanying Woodcut. It may be regarded as an imperfect 
example of the so-called ‘‘intermandibular arch” of the extinct 
ganoid, Onychodus, described by Prof. Newberry’ from the Corn- 
iferous Limestone of Ohio, and the Chemung Group of Delaware 
County, New York. 
The fossil is, for the most part, only displayed in section, owing 
to the unfortunate plane of fracture of the matrix ; but the upper- 
most of the vertical series of teeth, as preserved, exhibits the 
unbroken outer surface for about half of its length, and this enables 
Intermandibular Arch, or Presymphysial Bone, of Onychodus anglicus, A. 8. 
Woodw., Lower Old Red Sandstone Passage Beds, Ledbury, Herefordshire. 
Twice nat. size. [Grindrod Collection, University of Oxford. ] 
the cylindrical form and unornamented character of the dental crown 
to be determined. There is a curved plate for the attachment of the 
teeth, scroll-shaped in section, the attenuated lower extremity being 
considerably in-rolled. The teeth have the appearance of being 
directly fused to the base, arranged along its convex side; and they 
obviously decrease in size from above downwards, though the distal 
portions of all but the uppermost are considerably destroyed. The 
upper tooth, as already remarked, is slender and cylindrical in 
section, with a smooth surface, perhaps only marked with one faint 
longitudinal groove on each side; and the distal half of the crown 
is sharply directed upwards. Beneath this tooth are prominent 
remains of three others, similarly shaped, and closely placed together 
at their bases; and evidence of either one or two still smaller teeth 
is distinguishable yet more inferiorly. 
Ferruginous matter has penetrated the interstices of the fossil, 
1 J. S. Newberry, Geol. Survey of Ohio, vol. i. pt. ii. (Paleontology), pp. 296— 
302, plates xxvi., xxvii, 
