1869. ] DAVIDSON—PEBBLE-BED BRACHIOPODA. 79 
scribe it as such. But we have a British species of Orthis (O. spiri- 
feroides), in the Caradoc Sandstone, which exactly resembles it in 
outline and convexity. Otherwise I might believe, with my friend 
M. de Verneuil, that it was a Devonian fossil introduced into these 
beds. It would seem that there is at least one allied species of 
Spirifer in the French Silurian deposits, S. Davidis, Rouault.” - The 
Budleigh species, however, is quite distinct from Orthis ? spiriferoides. 
11. Sprrirera macropTEeRa, Goldf.?, var. microptera. Pl. LV. figs, 
21 & 22. 
Shell semicircular, much wider than long, valves convex, hinge- 
line as long as the width of the shell, cardinal angles acute, with mu- 
cronate wings; fold smooth, with a slight depression or flatness in the 
middle; lateral portion of valve ornamented with about twelve ribs, 
or twenty-four on each valve. Length 6, breadth 15 lines. 
This shell is not abundant; it has been found once or twice in the 
same pebble with S. Vernewilii and Rhynchonella inaurita. Tam not, 
however, quite certain with reference to the correctness of my iden- 
tification of it with Goldfuss’s S. macroptera; but I know of no 
nearer form with which it can be at present compared. 
12. SprrirERA octopricaTa, Sow.? PI. IV. fig. 23. 
In external shape the Budleigh specimens closely resemble the 
Devonian and Carboniferous species ; but some examples are also not 
unlike S. elevata of Dalman. It occurs sparingly in the same rock 
with a Strophomena, Orthis Vicaryi, and two or three other forms. 
It differs also in the respective number of lateral ribs. 
I could make out with certainty no more than the three species 
above recorded; but one or two imperfect internal casts have been 
found which may perhaps belong to another Spirifera. 
13. Nucteosprra Vicaryi, n. sp. Pl. IV. figs. 15-18. 
Shell transversely suborbicular; valves moderately convex, most 
so near the beaks. In the dorsal valve the mesial fold is wide and 
of small elevation, rising towards the front; beak of ventral valve 
small and incurved; surface smooth, marked by a few lines of 
growth. In the interior of the dorsal valve the bifid cardinal pro- 
cess projects considerably, while under it rises a narrow ridge which 
extends to the front and thus divides the shell into two portions! . 
The muscular impressions lie on either side of the posterior half of 
this ridge. In the interior of the ventral valve a mesial ridge is 
likewise present, which, as in the dorsal one, divides the shell into 
two equal parts. On either side are located the muscular im- 
pressions. ‘'wo examples measured respectively :— 
Length e breadth 9, depth 2 lines. 
e y; 6 lines. 
This remarkable species seems referable to the genus Nucleospira, 
and approaches, by its size and character, to WV. elegans, Hall (Pal. 
N, — vol, iii. p. 222, pl. xxviii. B, figs. 10 & 15). It varies in 
