94 JURASSIC RHYNCHONELLIDS 
OccURRENCE. According to Arkell (1933), the brachiopods are restricted to the 
“ore bed ’’ which he described as attaining a maximum thickness of 20 feet and as 
being a “‘ crumbling reddish-brown oolitic rock, full of shining pellets of ore’”’. The 
rhynchonellids are among the least abundant elements of a fauna which also includes 
the terebratulid Ornithella lampas (Sowerby), and various gasteropods, lamellibranchs 
and ammonites. 
Remarks. It has been decided to retain the specific name given by Rollier (1917) 
in preference to Rhynchonella pinguis Roemer and R. pinguis var. pectunculoides 
Etallon suggested by Davidson in view of the uncertainty attached to those names. 
If and when the latter species is revised, it may prove necessary to place the name 
hudlestoni in synonymy. This is considered unlikely, however, as the figures of 
pectunculoides given by Etallon (1861) appear to have finer ribs and a much stronger, 
more upright beak. Rhynchonella corallina Leymerie, the specific name suggested 
by Arkell, seems to be generally accepted as a synonym of R. pinguis Roemer, a 
species frequently quoted but greatly in need of elucidation and revision. 
Septaliphoria (?) septentrionalis sp. n. 
(Pl. 8, figs. 6-7) 
Name. Latin, septentrionalis—northerly ; the species is only known to occur in 
the north of Scotland. 
Diacnosis. Flattened, medium sized Septaliphoria-like form 
simple ribs ; width greater than length. 
STRATIGRAPHICAL RANGE. ? Upper Oxfordian—? Lower Kimmeridgian. 
TYPE SPECIMEN. Holotype, BB. 44175, collected from Alt-na-cuile, near Brora, 
Sutherland. 
DIMENSIONS OF HOLOTYPE. Length 2-37 cm, thickness 1-45 cm, width 2-86 cm. 
MATERIAL. Further 20 specimens collected by the author from Alt-na-cuile ; 
6 specimens from collection of Royal School of Mines, presumably from the same 
locality. All the specimens are preserved as sandstone casts. 
DeEscrIPTION. External characters. The shell is either equally biconvex or with 
a slightly more inflated brachial valve. The beak is quite strong and suberect ; 
details of the beak ridges and interarea are not preserved. 
The only ornament preserved is the strong, simple ribs. Some specimens possess 
a posterior smooth area but it is not certain whether or not this is a result of the poor 
preservation. A slight uniplication was probably developed in some specimens, but 
in the best preserved material the anterior commissure tends to be asymmetrical. 
DIMENSIONS OF FIGURED SPECIMENS. 
; I0-I5 strong, 
length thickness width 
2°40 cm 1-73 cm 2°75 cm 
2°35 cm I-42 cm 2°85 cm 
Internal characters. The preservation precludes serial sectioning and only very 
limited information can be obtained from the casts. 
