4 
ig 
i : 
TRANSACTIONS OF THE SECTIONS. 61 
Cyphaspis, Burmeister, 
is another example of this dorsal appendage. Several of the species that have 
been described show something of it when perfect. A fine series of the C. megalops, 
M‘Coy, from Dudley, in the collections of Messrs. Gray and Fletcher, have in each 
specimen a strong spine projecting from the 6th segment, which is the same segment 
in which they occur in the recent Spheroma, 
Encrinurus punctatus, a common Trilobite, has similar spines on the 7th and 10th 
thorax segments. Brontes spinifer, Barrande, and Sao hirsuta, ibid, have short 
spines on every segment. 
Motuusca. 
The collections in Kildare have also yielded a new and very interesting Cephalopod, 
of a group common in North America, but not in this country. The genus Lituites in - 
America coniains a group of closely-coiled species, the whorls being thicker than 
broad (instead of broader than wide, as usual in the genus), the siphon internal, and 
the septa waved backwards on the peripheral margin. They are distinguished as the 
genus Trocholites. One of these species, the Lituites (1.) planorbiformis, Conrad, 
was found by Prof. Sedgwick and myself at Bala, North Wales. The septa in that 
have but a very slight backward curvature on the outer margin. A second species, 
from the Chair-of Kildare, is different from either of the American ones. It is 
easily distinguished by the great depth of the backward curvature of the septa, form- 
Ing a complete sinus. It may be called 
Lituites hibernicus, sp. nov. 
Diameter 3ths of an inch, thickness nearly half an inch. Whorls 4 (or 5), their 
thickness much greater than the breadth. Umbilicus rather deep. The inner whorls 
much covered by the outer. Surface with faint lines of growth, nearly smooth. 
Septa rather approximate, and with a deep peripheral sinus. 
Pterotheca, new genus. 
I wish to propose the above name for a remarkable Pteropod mentioned in the 
Report of the last meeting of the Association as occurring in Canada, Ireland, and 
Wales. Of this beautiful fossil, originally described from a Tyrone specimen as a 
smooth Brachiopod, better specimens have been obtained in N. Wales, which show 
it to have been an animal closely allied to Cleodora, but distinguished from it and all 
allied forms now known by an extraordinary expansion of the sides or wings of the 
shell. The cavity for the animal is acompressed triangle, as in Theca, Cleodora, and 
others of the order; but the dorsal lamina is-much elevated above the flat ventral 
one, and the sides are furnished with a wing-like expansion almost to the curved tip. 
Species 1. Pterotheca transversa. Sides entire ; ventral lamina flat. Syn. Alrypa 
transversa, Portl. Geol. Rep. p. 455: As Cleodora transv. Salter, Rep. Brit. Ass. - 
1851, p. 64. 
Locality. Desertcreat, Tyrone. 
Species 2. P. corrugata, n. sp. Sides lobed, ventral Jamina somewhat keeled above. 
Locality. Caernarvonshire. 
On the supposed Action of Water in Geological Formations, and the Posi- 
tion of the Poles of the Earth. By W.D.Sautt, F.G.S. 
On the Conditions under which Boulders occur in Scotland. 
By James Situ, F.G.S., of Jordan Hill. 


On Certain Furrows and Smoothings on the Surface of Granite, caused by 
| Drift Sand, at the Cape of Good Hope. By Wiiv1am Srancer, M.D. 
It appears by the observation of the author that rocks are polished by the sand 
driven by the winds, and exhibit on a smaller scale similar effects to the polishing by 
glacial action. 
