542 BRITISH PALAZOZOIC FOSSILS. [GasTERoPopDA. 
of S. tabulatus cut and neatly cemented to their centres to form a spire. Small specimens are very analogous to 
some of the varieties of S. pentangulatus with elevated spire, but seem distinct by the outward sloping of the 
upper tabulated portion of the whorls at that age. 
Position and Locality.—Common in the dark lower carboniferous limestone of Kendal, Westmoreland ; not 
uncommon in that of Lowick, Northumberland. 
Genus. ENCYLIOMPHALUS. See page 301. 
ENCYLIOMPHALUS AQUALIS (Sow. Sp.) 
Ref, and Syn. = Planorbis id. Sow. Min. Con. t. 140. f. 1; ? = Porcellia levigata YEveill. Mém. de la Soe. Géol. 
de France, Vol. II. t. 2. f.12 and 18 ; ! = Bellerophon levigatus d’Orb. Monog. Bell. t. 6. f. 24 and 25. 
Dese.—Discoid, of five or six slightly disconnected whorls; spire sunk below the level of the last turn ; 
mouth circular, entire ; whorls almost perfectly cylindrical, an almost imperceptible flattening on the upper third 
of the body-whorl; surface crossed by direct, minute strize of growth. Diameter one inch three lines, propor- 
tional width of last whorl 5, space between last and penultimate whorl ;%, depth of last whorl 3%. 
The distance separating the whorls of this species is so small that it seems to have been overlooked by the 
various authors alluding to it. 
Position and Locality —Rare in the carboniferous limestone of Isle of Man; in the carboniferous limestone 
of Kendal, Westmoreland. 
ENCYLIOMPHALUS CRISTATUS (Phill. Sp.) 
Ref. and Syn. = Euomphalus id, Phill. Geol. York. Vol. IJ. t. 18. f. 5, = Phanerotinus id. Sow. Min. Con. 
t. 624. f. 1. 
Desc.—Spire of about three very widely disjoined whorls, not raised as high as the edge of the basal whorl 
(rarely more than one and half turns preserved); under side of the volutions moderately and evenly convex ; 
upper and outer aspects much more gibbous than the under, from an obtuse ridge between them; the outer aspect 
moderately inclined and smaller than the upper; the periphery obtusely angulated considerably below the middle, 
and giving off there in all the whorls a strong, obscurely double, largely-dentated crest, flattened in the plane of 
the volutions, the denticles seeming subalternate, triangular, about twice as long as the width of their base, the 
length nearly twice the diameter of the whorl from which they originate ; section of each whorl slightly oblique, 
ovate (with the exception of the obscure angulation between the upper and outer aspects), the pointed portion 
corresponding with the crest at the periphery; shell thick, marked with strong imbrications of growth, arching 
forwards towards the crest on the under side, and backwards towards the obtuse keel, and then forwards to the 
crest on the upper side. Diameter of large specimen, excluding the crest, eight inches six lines, proportional 
width of last whorl ;%, distance between last and penultimate whorl *, diameter of penultimate whorl ;4, 
depth of last whorl about °. 
The spire of this species scarcely ever rises to the level of the obtuse keel near the middle of the upper 
aspect, from which the outer and upper aspects slope with moderate convexity. Very rarely more than one 
whorl is preserved in most specimens, from the tube after that length being divided by strong, transverse, 
imperforate septa, as in many other slender Gasteropods. The great size and the large double strong shelly 
keel of flat triangular denticles easily distinguish this species from all others. Mr Sowerby, in proposing the 
genus Phanerotinus for this shell, supposes Lncyliomphalus to be less curved, and to differ besides in having 
a thinner shell; but the Hncyliomphalus Scoticus (M°Coy) has as thick a shell in proportion to its size, and 
there is no tangible generic difference in the amount of curvature. 
Position and Locality—Not very uncommon in the dark lower limestone of Kendal, Westmoreland. 
