1869. ] DAVIDSON—-PEBBLE-BED BRACHIOPODA. 87 
of the shell; area moderately wide, marked with perpendicular pa- 
rallel lines, and with two deep circular pits (elevations on the cast), 
one on each side of the centre, divided by a small flattened space ; 
the saucer-shaped muscular scars are large, and, in the shell, divided 
by a median ridge. 
Mr. Vicary found this single specimen associated with 2. ovalis. 
The peculiar shape of its area and accompanying pits seems to 
distinguish it from other known forms of the genus, although it is 
impossible to offer a complete description of its characters. 
33. STREPTORHYNCHUS CRENISTRIA, Phil. Pl. V. fig. 26. 
Spirifer crenistria, Phil. Geol. of Yorkshire, vol. 11. p. 216, pl. 9. 
fig. 6; Streptorhynchus crenistria, Dav. Dev. Mon. p. 81, pl. 
xvii. fig. 7. 
Of this species, only a fragment of the exterior of one valve has 
been found. It seems to agree entirely with similar portions of S. 
crenistria, with which we have compared it. The shell has been 
fully described in my monograph. It was found along with Spirifera 
Vernewlu, Rhynchonella imaurita, and Productus Vicaryi, and is 
consequently a Devonian species. 
34. Propucrus Vicaryi, Salter, sp. Pl. VI. fig. 14. 
Leptena Vicary?, Salter, Quart. Journ. Geol. Soc. vol. xx. p. 296, 
pl. xvii. figs. 16-17. 
Well described and figured by Mr. Salter, but incorrectly identified 
as a Leptena, while all its external and internal characters show it 
to be a Productus; in addition to the cardinal spines, we find the 
large cardinal or divaricator muscular impressions of the genus Pro- 
ductus. These finely striated scars were correctly drawn by Mr. 
Salter in 1864, In his description he states, “I know no Silurian 
species, except the small LZ. quadrata of Russia, and L. tenwicincta 
of Britain, which resemble this form; both are much smaller and 
less gibbous.” But these last belong to the genus Leptena, and are 
quite different both as to shape and character, while the so-called 
Leptena Vicaryi is a well-characterized Productus. P. Vicaryi is 
not very rare at Budleigh-Salterton, and is found associated with 
Spirifera Verneuili, Rhynchonella inaurita, and Streptorhynchus cre- 
nistria, all well-known Devonian species. 
35. CHoneTES, sp. Pl. VI. fig. 13. 
Of this small species of Chonetes several specimens have been 
met with by Messrs. Edgell and Vicary in one or two pebbles; and 
as it was associated with Rhynchonella inaurita, it is no doubt of 
Devonian age; but as the exterior has not been discovered, we can- 
not refer it with certainty to any of the described species. The 
casts are marginally semicircular; hinge-line straight, with acute, 
slightly projecting cardinal angles; ventral valve evenly convex. 
Length 3, width 4 lines. In external shape it resembles some De- 
vonian casts of CO. hardrensis, but is a smaller shell. 
Besides the species above enumerated, Mr, Vicary has found in- 
