GastERopPopA. | UPPER PALZOZOIC MOLLUSCA. 539 
Position and Locality.—Rare in the lower carboniferous limestone of Lowick, Northumberland. 
Explanation of Figures.—Pl. 3. H. fig. 3, natural size, seen from above; fig. 3a, profile; fig. 3 4, 
portion of surface magnified two diameters ; fig. 3c, viewed from below. 
STRAPAROLLUS? CROTALOSTOMUS (J/°Coy). 
Ref. and Syn. = Euomphalus id. M°Coy, Synop. Carb. Foss. Irel. t. 7. f. 4. (very small specimen). 
Desc.—Discoid, very much depressed; spire originally of about six whorls (rarely more than one and half 
preserved) ; spire varying from the very slight elevation of 190° to depressed below the level of the body-whorl ; 
upper portion of each turn obscurely flattened, the flattened or slightly convex portion bounded by a very obtuse, 
obscure angulation, placed at the outer third of the upper aspect of the whorls; periphery very convex in the 
middle, under side broadly convex; umbilicus completely exposing all the turns, its margin convex, undefined : 
mouth transversely oval, scarcely, if at all, indented by the preceding whorls; edge dilated, trumpet-shaped, with 
a shallow sinus, coinciding with the obscure angulation bounding the flattened upper part of the whorls. Surface 
at all ages crossed by exceedingly coarse, rugged, irregular imbrications of growth (remains of the dilated lip). 
33 0 
Average diameter eight inches, proportional diameter of last whorl %, diameter of penultimate whorl “,, diameter 
of umbilicus =, height of last whorl =. 
This species is distinguished from the S. tabulatus, to which it is most allied, by its great size, the depres- 
sion of its spire, the very obscure keel, and its being placed so much nearer the outer margin of the whorls, the 
greater depression of the whorls, and consequently wider transyersely oval mouth, and above all, by the extreme 
rugosity of its surface, (which in specimens of even three or four inches in diameter almost equals that of the 
Silurian Hwomphalus discors,) which is produced by the edges of the peculiarly dilated margin of the mouth : this 
character is represented in the ower figure of t. 638 of the Mineral Conchology under the name Cirrus tabulatus, 
being confounded with the upper figure representing a large example of that comparatively smooth, high-spired, 
and strongly-angulated species. As from the transverse septation common in the terminal whorls of this genus 
so large a species as this would rarely have one, or one and half turns perfect, the dealers frequently adapt the 
spires of three or four different specimens of various ages, to render the shell apparently complete, often termi- 
nating the centre of the spire with a specimen of S. tabulatus, which may have deceived Mr Sowerby, and which 
would have deceived me had I not known the species before. 
Position and Locality—Not uncommon in the lower carboniferous limestone of Kendal, Westmoreland. 
STRAPAROLLUS DIoNysII (de Montf.) 
Ref. and Syn.—De Montf. Conch. Syst. Volk. II. p. 174 = Cirrus rotundatus Sow. Min. Con. t. 429. f. 1 and 2; 
Phill. Geol. York. Vol. IT. t. 13. f.15. 
Dese.—Conical, spire of six or seven gradually increasing whorls, varying greatly in height; apical angle 
varying from 75° to 120°; usually simply rounded below, and gently convex above and on the turns of the spire, 
with the sutures sharply impressed; sometimes a very slight flattening observed on the sutural third of the body- 
whorl, and occasionally the sutures slightly adpressed; mouth obliquely oval, nearly circular; umbilicus very 
large with a rounded margin, exposing all the whorls. Surface marked with slightly irregular, slightly oblique, 
obsolete lines of growth. Average diameter one inch* three lines, proportional width of last whorl ;;, total 
height “, height of last whorl “4, width of umbilicus 4. Depressed variety averaging one inch six lines in 
diameter, proportional width of last whorl *,, total height =, height of last whorl 3, width of umbilicus ;j. 
Under the head of S. acutws I have made some observations on the gradual passage apparently indicated by 
many specimens between that species and the present, and also the approximation of both forms to that which 
I figured under the name Z. anguis. A variety with the base slightly flattened occurs in the Lowick lime- 
stone. All the varieties of form have occasional examples shewing a few obtuse obscure spiral lines. 
Position and Locality—Very common in the lower carboniferous limestone of Kendal, Westmoreland ; 
not uncommon in that of Derbyshire; rare in the dark lower limestone of Lowick, Northumberland ; in the red 
earboniferous limestone of Closeburn, Dumfriesshire ; in the red siliceous limestone of Breedon, Leicestershire. 
