536 BRITISH PALAXOZOIC FOSSILS. [GasTERopopa. 
spicuous oblique lines of growth; mouth longitudinally ovate; columella thickened, flattened; no umbilicus. 
Length of small specimens four and a half lines, proportional width =, length of last whorl, or mouth, {2 space 
between the last and penultimate sutures =, width of mouth *3. 
Occasionally, as M. de Koninck remarks, the two rows of tubercles on the body-whorl are connected by 
tolerably distinct ribs, and sometimes the anterior row of tubercles disappears, leaving only the row round 
the sutures, forming the variety called Turbo semisulcatus by Phillips. I have not yet clearly'seen the 
columella, 
Position and Locality —V ery rare in the lower carbonifetous limestone of Derbyshire. 
Turso? HELICINUS (Schlot. Sp.) 
Ref. and Syn. = Trochilites helicinus Schlot. Petrefactenk. p. 161. = 7. minutus Brown, Manch. Geol. Trans. 
Vol. I. t. 6. f. 4, 5. = 7. Meyeri Miinst. Goldf. Pet. t. 192. f. 14. (an elongate variety has the MS. name 
T. bistriata Miinster, in his collection) = 7. Mancuniensis Brown, Manch. Geol. Trans. Vol. I. t. 6. f. 1, 2,3. 
King, Perm, Foss. t. 16. f. 19, 20. + (7. Thompsonianus King, Perm. Foss. t. 16. f. 23, 24. = 7. Tunstal- 
lensis Howse, Trans. Tyn. Nat. F. Club, Vol. I. p. 240) + 7. Taylorianus King, Perm. Foss. t. 16. 
f. 25, 26; 7. Helicinus (Schlot.) King, Perm. Foss. t. 16. f. 21, 22. 
Desc.—Ovate ; spire short, conic, varying in acuteness ; apical angle varying from 60° to 86° (most usually 
the latter) ; whorls, about five, tumid, rounded, rapidly enlarging ; body-whorl tumid, and rounded below into a 
very small, elongate narrow umbilicus, immediately behind the pillar-lip, which is thickened and slightly flattened 
in the anterior half, thinner or obsolete behind; mouth very broad, ovate; sutures deeply channelled. Surface 
with strong spiral ridges, three on each of the spiral whorls, separated by broad, subequal, flattened or concave 
spaces; the upper ridge much smaller than the other two; body-whorl with eight or nine strong spiral ridges, 
the two or three on the most prominent part of the whorl largest, gradually diminishing on the base ; the spaces 
between the ridges marked with obliquely longitudinal fine plicee of growth. Length and width of average 
33 
specimen three and a half lines, height of mouth &, height of penultimate whorl =, width of mouth =. 
In this species the spiral whorls often seem to have only two keels, from the small upper keel becoming 
obscure ; in partially decomposed specimens, such as that figured by Goldfuss, the spiral ridges on the base become 
obscure. I have seen in some specimens traces of a small spiral ridge between each of the larger pairs. 
Specimens named Turbo Mancuniensis by Prof. King, and sent to the Cambridge Collection, agree exactly with 
the original description, but differ in no respect from the 7’. helicina. 
Position and Locality —Common in the Permian magnesian limestone of Humbleton. 
Genus. STRAPAROLLUS (MontfZ:) 1810. 
Syn. < Euomphalus Sow. 1814 < Cirrus Sow. 
Gen. Char.—Discoid, depresso-conic, generally smooth or transversely striated ; umbilicus very wide, ex- 
posing the whorls, which are either rounded or angulated; mouth indented by the penultimate whorl ; peri- 
treme simple, thin, most so on the left side. 
M. de Koninck and M. d’Orbigny have drawn attention to de Montfort’s name Straparollus, having the 
priority over Sowerby’s Huomphalus; and from his description and figure there can be no doubt of his genus 
embracing some of Sowerby’s types of Huomphalus and Cirrus; I have retained the name Huomphalus for 
certain Delphinula-like species, with thick, circular, entire peritremes, and confined Straparollus to those with 
the thin peritreme and indented mouth, &c., as in de Montfort’s original type the S. Dionysit. They most nearly 
resemble Sol/ariwm, but have neither the strongly crenulated edge to the umbilicus, nor the notch in the anterior 
edge of the lip which produces it. 
