1869.] DAVIDSON—PEBBLE-BED BRACHIOPODA. 81 
ornamented with from sixteen to twenty simple angular ribs, of which 
from three to six of the largest occupy the fold, while from two to 
five furrow the sinus, the ribs on the lateral portions of the shell 
being narrower. Length 9, breadth 10, depth 6 lines. 
In size, shape, and character this shell entirely resembles R. in- 
aurita, Sandberger. It is also not unlike R. daleidensis, Roemer, and 
Rh. liwonica, v. Bueh, but seems to be distinguishable from both by the 
shape and character of its mesial fold, which is regularly incurved, 
and not recurved upwards near the front as is the case with the 
last two species. i. inaurita occurs abundantly under the condition 
of internal casts and external impressions, and is associated with 
Sp. Verneuilii, R. Valpyana, Streptorhynchus crenistria, Productus 
Vicaryi, and Crania transversa. It is consequently a well-defined 
Devonian species, and as such it was identified by M. de Verneuil 
in 1863. 
In his paper on the Budleigh-Salterton fossils Mr. Salter describes 
and figures a single internal cast of the dorsal valve of this species, 
as well as the cast of what he takes to be another species; but as 
the last-named specimen has been lost or mislaid, I could not exa- 
mine it, and consequently cannot express any opinion with reference 
to its claims as a separate species. I will therefore simply reproduce 
Mr. Salter’s description. 
“« Rhynchonella, sp.,” Quart. Journ. Geol. Soc. vol. xx. p. 297, 
pl. xvi. fig. 14. 
‘A remarkable fossil, which, if it were more perfect, should 
receive aname. It is singularly inflated, both on the sides and in 
the great dorsal fold, which occupies one-half of the width, and is 
+5 inch long, and scarcely so wide, while the depth of the single 
dorsal valve we possess is ;4,. The shape is broad-ovate, the beak 
much pointed and rather produced, the sides arched, inflated, and 
separated by a rather broad depressed space from the raised sinus, 
which has four strong plaits. The sides are only faintly ribbed. 
The front is strongly incurved.” 
18. RayncHoneLLA ELLIPTICA, Schnurr? PI. V. fig. 4. 
Along with R. inaurita, another similarly shaped shell is occa- 
sionally met with, which may perhaps be an extreme variation 
in form of the last-named species, but may be distinguished from 
it by a greater number of ribs on the mesial fold. It is nearly 
circular, or a little broader than long, and ornamented with about 
twenty-eight ribs on each valve, of which nine occupy a slightly 
raised mesial fold. Length 8, width 84 lines. 
This is certainly a Devonian species, as it occurs in the same 
boulders with R. inawrita and Spirifera Verneuilii ; we have provi= 
sionally identified it with R. elliptica of Schnurr? 
19. Rayncnonsxa, sp.? Pl. V. figs. 5 & 6. 
Of this species two internal casts have been found by Mr. Vicary ; 
but, as no external impressions accompanied them, I dare not attempt 
their identification. In shape it is somewhat pentagonal, wider than 
VOL, XXVI,—PART I. G 
