TRANSACTIONS OF THE SECTIONS. 97 
of North Cave is built on a thick drift of the Modiola minima bed, excessively crowded 
with a doubtful shell called provisionally a Posidonomya; and between North and 
South Cave, in “ Sandy Lane,” is an extraordinary drift of Gryphea ineurva. These 
two drifts are remarkably independent of each other. 
II. There seems to be no facility for examining the upper beds of the lower lias, 
though that formation is a mile across. The middle lias forms a beautiful bank on 
the east side of Hotham Park, and sections can be seen near North Cave, in a marl- 
pit and a road-side cutting. ‘The beds change upwards thus—from blue shales at the 
bottom, through brown shales and sand with irregular broken bands of nodular clay~ 
ironstone, to a hard rock-bed of the true marlstone 2 or 3 feet in thickness, which 
again is capped at the top of the ascent by a very rubbishy ferruginous rock, the 
lowest member of the ironstone series. These ironstones contain a good many fossils ; 
but are most distinguished by Belemnites and Rhynchonella tetraedra. Many fossils 
also of the marlstone band have been found in drift between Hotham and Newbald, 
In the same drift are shells of the upper lias and Oxford clay, though neither of 
these rocks is yet known with certainty to exist in sttw near Hotham. 
III. Between the middle lias and inferior oolite there is a remarkable thin band 
of marly limestone, which is called at present the “ Ligniferous marl.” It has a very 
freshwater appearance, and contains fragmentary remains of ferns and other land 
plants. Its marine remains consist chiefly of two species of Urchins, with Pinne, 
Pectens, and Modiolz, each of a single species, and always in good preservation. 
This band seems never to have been described before in any locality. 
IV. The oolite of ‘‘ Hotham Quarry” appears to be inferior oolite, and a distant 
equivalent of the ‘‘Roestone” of Cheltenham. It is strange that this bed should have 
been said to be wholly restricted to the vicinity of the town of Cheltenham, Its fos- 
sils, and more or less of its structure, may be seen in other places; as at Haresfield 
in Gloucestershire, and at Hotham. At Hotham perhaps the most common form is 
Pygaster semisulcatus; which is at present supposed, on the best authority, to be 
strictly confined to the inferior oolite. The fossils associated with it lead to the same 
conclusion : they are most of them common at Cleeve and Crickley, near Cheltenham. 
On a New Genus (Dimorphodon) of Pierodactyle, with remarks on the Geo- 
logical Distribution of Flying Reptiles. By Professor Owen, M.D., 
ILD. PRS. 
The author exhibited a drawing of the skull and some of the wing-bones and other 
limb-bones of a Pterodactyle which he had obtained during a recent visit to Lyme 
Regis, in Dorsetshire. The specimen in question was discovered in the lower lias 
of that locality, and had been purchased for the British Museum. The fore-part of 
the cranium was preserved, anterior to the orbit, measuring in length 6 inches. 
This was peculiar for the vast expanse of the long nostril, which was oval, and 
measured 3 inches by 14 inch; the antorbital vacuity, divided by a slender 
oblique bar from the nostril, was triangular, 1 inch 5 lines in long diameter ; 
the solid part of the premaxillary in advance of the nostril measured only 1 inch 
9 lines in length, or little more than half the length of the nostril—proportions 
which had not been previously observed in any Pterodactyle. The largest teeth 
were implanted in this part of the upper jaw. One, which had been displaced and 
showed the oblique basal cavity and depression, formed by a successional tooth, 
measured more than an inch in length. The largest exserted crown of a premaxil- 
lary tooth in place measured 7 lines. A tooth situated 3} inches behind the first 
tooth, had a crown 5 lines in length; then followed three shorter teeth, and behind 
these, and below the antorbital vacuity, were several small teeth, with intervals. 
The dentary bones of the lower jaw were preserved, measuring 6} inches in length. 
These exhibited a peculiarity of dentition not previously described or figured ; viz. 
two long prehensile teeth at the fore-part of each ramus, separated by an interval of 
half an inch, and followed, after a similar interval, by a series of much more minute 
and close-set teeth, with straight, short, compressed, lancet-shaped crowns, none of 
which exceeded a line in length. Forty-five of these teeth might be counted in aa 
alveolar extent of 2 inches 9 lines, and in a part of the dentary bone averaging 8 lines 
in en This character of dentition was such, that the figure published by Dr. 
58. ri 
