340 Thos. Davidson—Brachiopoda of Brittany and S. Devon. 
Cornish rocks, it is evident that we must look to other sources for 
the derivation of the great bulk of the Silurian pebbles accumulated 
at Budleigh Salterton. It is probable that but a proportionately 
small number, if any, of the pebbles were actually drifted from 
Cornwall to South Devon, and that it is to France, or to an extension 
of Silurian and Devonian rocks that may have existed in the Channel 
and nearer to Devonshire, that the pebbles now accumulated near . 
Budleigh Salterton were mainly derived. This is likewise the view 
taken by M. de Tromelin and M. Lebesconte, and is reciprocated 
by most of our British geologists who have interested themselves in 
the question.! a 
It is also remarkable that quartzite pebbles exactly similar to those 
that occur at Budleigh Salterton and containing Orthis Budleighensis 
have been found in drift deposits in Warwickshire, near Leicester, 
near Nottingham and Birmingham. Others with Zingula Lesueurt in 
Warwickshire, and near Birmingham. While quartzite pebbles 
with Sp. Verneuilit have been picked up near Birmingham, and one 
with a Discina Vicaryi on the Chesil Bank. 
Drinozotus Brimonti, Rouault sp. Pl. X. Figs. 1—6. 
Lingula Brimonti, Rouault, 1850. Lingula Hawkei, Salter and Day. (not of Rou.). 
I never felt satisfied that this remarkable fossil belonged to the 
genus Lingula, and both M. de Tromelin and Prof. Bayle hinted to 
me that it was in their opinion not a species of Zingula, and that a 
new genus would have to be created for its reception. 
Thanks to the liberality of M. Lebesconte, I have recently been 
able to study a large series of bivalve specimens as well as finely 
preserved internal casts of both valves, and at once perceived that the 
species possessed all the characters of Hall’s genus Dinobolus, and of 
which genus Prof. King and myself had given an elaborately 
illustrated description in the Quarterly Journal of the Geological 
Society, vol. xxx. 1874. We can therefore dispense with burdening, 
the nomenclature with another new genus. Dinobolus Brimonti is 
very variable in its shape, but generally more or less quadrate, with 
roundedangles; sometimes it assumes atriangular form (PI. X. Fig. 4). 
The dorsal valve is the deepest and most convex or inflated, a 
median longitudinal depression being observable in the ventral 
valve. The beak projects moderately (Fig. 3), and although smooth 
exteriorly, the surface of both valves is strongly marked with 
deeply indented concentric lines or projecting ridges. In the interior 
of the ventral valve, we observe a well-defined platform on which 
are situated the lateral and anterior muscular scars o and n, as well 
as the crescent r. On the interior surface of the dorsal valve, in 
addition to the anterior and median \y-shaped muscular scars 0 and m; 
1 M. Lebesconte informs me that fossiliferous sandstones and quartzites haye been 
found in the following localities, in Normandy and Brittany—1l. Grés Armoricain, 
Pontréan, Pléchatel, Guichen, Sion, Chateaubriant, Provostais, Laillé. 2. Grés de 
May, La Bouexiére, St. Germain-sur-Ile, May, Jusques. Grés Devonien, Gahard, 
St. Aubin d’ Aubigné. 
