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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [JunO 19, 



true place of Oldhamia, and, if possible, of the mythical Pdlceopyge^ 

 in these old red rocks. He has been rewarded, during the search, by- 

 many additions to the Menevian fossils, found at successively lower 

 and lower horizons, in the grey rocks which form the passage from 

 the Lower to the Upper Cambrians. But, until quite lately, not a 

 vestige had occurred to him in the actual red rocks themselves. 



The fossil is but a small one, a line and a half long ; but it is 

 unquestionably a Lingulella, and apparently of the same species as 

 one very common in the lowermost of the layers which have yielded 

 Paradoxides, and the fossils of which wiU. be described in our next 

 memoir. With the Paradoxides Hicksii, Salter (the species for- 

 merly published in Siluria, 2nd edit., as P. Forchammeri?), several 

 species of shells, Brachiopod and Pteropod, occur — and among them 

 a Lingulella, of which figures and a description are appended, and 

 which appears to be the same as that now found 200 feet lower 

 in the red Cambrian slates. 



Lingulella eereuginea, Salter, spec. nov. Pig. 1. 



Length fully 2 J lines. Perm ovate-oblong, the front rather obtuse, 

 but not straight-edged; the sides nearly parallel; the obtusely 

 pointed beak includes an angle of about 75°. Generally convex, 

 especially down the median area ; the sides bevelled obliquely ; the 

 surface concentrically andvery finely striated; the inner surface rather 

 coarsely sulcate concentrically, indicating close ridges or sharp waves 

 of growth upon the outer surface (not visible in our specimens). 

 The inner surface (and probably the outer) shows radiating lines 

 (rather coarse ones) over the median area, but not on the sides. 



The pedicle -groove is so wide and pyramidal as to open at an 

 angle of 40° ; and its edges are so strongly pronounced as to give the 

 appearance of hinge-plates. A short median ridge divides this area, 

 and extends but a very short distance. A specimen, apparently of 

 the shorter valve, has also a median line, but fainter and longer. 

 This is uncertain, the specimen being much crushed. 



Log. Lowest strata of the black flags in the Menevian group, Pen- 

 y-pleidiau, St. Davids. 



Pigs. 1-3. — Lingulella ferruginea, Salter. 

 2 3 1 



Fig. 1. Lingulella ferruginea, Seiltei: N,atural size. 



2. L. ferruginea, var. ova lis, Hicks. Natural size. 



3. The same, magnified. 



