188 BRITISH SILURIAN BRACHIOPODA. 
the escarpments bordering the North Esk River, not very far from the Bevelaw Reservoir 
in the Pentland Hills, where also it was discovered by Mr. A. Geikie. We are not at 
present acquainted with any other British or foreign locality. 
RHYNCHONELLA SaLTERI, sp. nov. Pl. XXIV, figs. 19—20. 
Spec. Char. Shell small, pentagonal, slightly wider than long, front line straight, 
tapering at the beaks. Valves moderately convex, smooth to about half their posterior 
length; fold in the dorsal valve wide, and formed of three ribs, while the lateral portions 
of each valve are either smooth or with one or two short ribs in the contiguity of the 
margin. In the ventral valve two ribs occupy the sinus; beak short and incurved. 
Length 4, width 43, depth 23 lines. 
Position and Locality—lIt occurs in the Caradoc at Penwhapple Glen, near Girvan, 
in Ayrshire, and at Boduan, in Carnarvonshire, both the figured specimens are preserved 
in the Museum of the Geological Survey. 
RuYNCHONELLA ? aMULA, Salter, MS. Pl. XXIV, fig. 21. 
RHYNCHONELLA ®MULA, Salter. Catalogue of the Collection of Fossils in the Museum 
of Practical Geology, p. 7, 1865. 
Spec. Char. Subpentagonal, slightly wider than long. Ventral valve uniformly 
convex and smooth to about half its length from the beak; mesial sinus moderately 
concave, commencing at the front margin and extending to rather more than one third of 
the length of the valve, with a wide central rounded rib; there are two or three short ribs 
also close to the margin on each of the lateral portions of the valve; beak short, closely 
incurved down to the umbone of the opposite valve. Dorsal valve convex, with a rather 
wide, much elevated mesial fold, which, commencing at about half the length of the valve, 
becomes biplicated as it reaches the front ; two short rounded ribs also exist on each of the 
lateral portions of the valve, but are confined to the contiguity of the margin. 
Length 4, width 5, depth 8 lines. 
Oés. ‘This small species is easily distinguished by its shape from our other Silurian 
forms. One can perceive, also, through the transparency of the shell, a straight line 
extending from the extremity of the beak and umbone to about half the length of the 
valves, and indicating the presence in the interior of the valves of short septa or ridges. 
It also bears resemblance to some varieties of Camarophoria globulina; and it is with much 
uncertainty that we provisionally place it under Rhynchonella. 
Position and Locality. It occurs in the Caradoc at the Chair of Kildare, in Ireland, 
and specimens may be seen in the Museum of the Geological Survey. At page 7 of the 
