78 DEVONIAN FAUNA. 



Locality. — One specimen in the Porter Collection in rubbly brown stone from 

 Pilton. 



Remarhs. — This fossil is distinguished from 8. mimus, n. sp., by the great 

 regularity, prominence, and number of its ribs. Thus it approaches Cardinia 

 Devonica, Geinitz,^ but shows little sign of the lessening of the ribs on the marginal 

 parts or of any median depression, and is further distinguished by its stronger 

 keel and rounded base, and by the ribs being absent on the postero-superior region. 



From Leptodomus constricta ^ it is distinguished by much more numerous ribs, 

 lower umbo, and the absence of a median constriction. 



Sanguinolites angustatus, Phillips, sp.,^ the type of the genus, is much more 

 transverse; and S. discors, M'Coy,* (Fischer's type), is very similar, but longer 

 and more rounded in front. 



2. Sanguinolites mimus, n. sp. (MS. Museum of Practical Geology). Plate IX, 



figs. 4, 6, 7 ? 



Description. — Shell of medium size, transverse, convex, suboval. Umbo wide, 

 depressed, flattened, proximate, situate at the anterior fourth of the length. 

 Anterior side somewhat produced, flattened. Anterior margin obliquely convex 

 below. Inferior margin long, slightly convex. Posterior margin roundly convex. 

 Hinge-margin long, straight, slightly oblique. Contour of back vertically convex, 

 horizontally slightly convex, but becoming steeply concave in front of umbo, and 

 gently concave in the postero-superior slope. Postero-superior slope bounded by 

 a convexity or incipient keel from rear of umbo to postero-inferior point, which is 

 followed above by a linear concave depression running from beneath the umbo to 

 the upper part of the posterior margin, and above that by a rounded thickening of 

 the shell over the hinge-margin. Surface bearing about seventeen rather unequal 

 and irregular concentric rounded ridges, separated by rather wider concave 

 intervals and being smallest near the umbo, occasionally divaricating in front and 

 becoming suddenly faint and invisible on the postero-superior slope. Minor 

 ornamentation (at least on posterior parts) consisting of crowded microscopic 

 transverse lineations. 



Size of left valve. — Height 16 mm., length 34 mm., depth 5 mm. 



Localities. — In the Museum of Practical Geology is a specimen from Croyde ; 



1 1853, Geinitz, ' Verst. Grauwack Sacbsen,' pt. 2, p. 4G, pi. xii, fig. 3. 



2 1841, Phillips, ' Pal. Foss.,' p. 36, pi. xvii, fig. 58. 



3 1836, Phillips, ' Geol. Yorks.,' vol. ii, p. 208, pi. v, fig. 2. 



* 1844, M'Coy, ' Synopsis Carb. Fo3S. Ireland,' p. 49, pi. viii, fig. 4. 



