ORTHID A. 235 
unknown strata from the general form of a shell without strict attention to specific 
differences ; as, had this species been found alone, most palzontologists would have 
referred it to the Carboniferous period.” The only difference I can see between the 
Portuguese specimens and those found at Budleigh-Salterton is that in the first the 
shell is broadest anteriorly, whilst in the last it is more uniformly transversely oval ; and, 
indeed, if the English and Portuguese specimens belong to the same species as that 
described from Brittany we would certainly have three distinct varieties, one of which 
would be peculiar to each of the three localities above named. 
Position and Locality. Of the shell under description I have examined a number of 
internal casts and external impressions, collected by Messrs. Vicary, Valpy, and Winwood, 
from the ‘“‘ Pebble-bed” of Budleigh-Salterton, in Devonshire. The pebbles and boulders 
are erratic, and seem in that locality to have been derived from rocks of two distinct 
periods. ‘Those, however, containing the O. Berthoisi are quartzites, or compact reddish 
sandstones of perhaps the Llandeilo age, but no rock x si¢w hitherto discovered in Great 
Britain has furnished us with the species. The foreign localities of this species have 
been already recorded. 
Orruis Vaupyana, sp. nov. Pl. XXXII, figs. 29—83. 
Spec. Char. Semicircular, or transversely oval, wider than long; hinge-line a little 
shorter than width of shell. Ventral valve evenly and moderately convex ; beak small, 
incurved ; area narrow; fissure triangular, open. Dorsal valve slightly convex, area 
linear. Surface of both valves covered with numerous small radiating ribs, each principal 
one bifurcating two or three times before attaining the margin, so as to form small 
clusters of strize. In the interior of the dorsal valve a small bifid cardinal process, forming 
the posterior extremity of a small longitudinal ridge, is situated between two very small 
brachial processes. In the interior of ventral valve the muscular area is small. 
Length 8, width 10 lines. 
Obs. ‘The festooned appearance of the ribs in many specimens of this species easily 
distinguishes it from O. intercostata, Portlock. ‘The muscular impressions are very faintly 
marked. 
Position and Locality. Several internal casts and external impressions of this shell 
were found by Messrs. Vicary and Valpy at Budleigh-Salterton, in boulders which are 
supposed to be of the same age as those containing Orthis Berthoise. 
