304 BRITISH PALAZOZOIC FOSSILS. [GASTEROPODA. 
HoLoPELLA INTERMEDIA (M/°Coy). PI. 1. L. fig. 16. 
Ref.—Id. M°Coy, Ann. Nat. Hist. 2nd Series, Vol. VII. p. 47. 
Sp. Ch.—I provisionally give this name to a species agreeing exactly, so far as I can see, with the 
H. obsoleta (Sow. sp.), but having an apical angle of 30°, being thus exactly intermediate between it and the 
H. conica (Sow. sp.), striking the eye as manifestly shorter than the former, and more slender than the latter. 
Length about seven lines, proportional width 5, length of last whorl =. 
Position and Locality—Not uncommon in the state of casts in the Upper Ludlow of High Thorns, 
Underbarrow, Kendal, Westmoreland. 
Explanation of Figure.—P\. 1. L. fig. 16, natural size. 
HoLoPELLA MONILE (M°Coy). PI. 1. K. fig. 32. 
Ref—Id. M°Coy, Ann. Nat. Hist. 2nd Series, Vol. VII. p. 48. 
Sp. Ch.—Very slender, apical angle about 10°; spire of about nine whorls (six preserved); each turn a 
little wider than long, exceedingly convex; sutures deep, simple. Length three and half lines, proportional 
width +, length of last turn ;;;. 
The small size, extremely slender form, and very convex whorls, render it impossible to confound this 
with any other species. 
Position and Locality.—Rare in Bala schists, Selattyn Road, S. of Llangollen, N. Wales. 
Explanation of Figures.—P1. 1. K. fig. 32, natural size ; fig. 32 a, magnified. 
HoLoPELLA OBSOLETA (Sow. Sp.) 
Ref. = Turritella Id. Sow. Sil. Syst. t. 3. f. 7a. 
Sp. Ch.—Elongate, spiral angle about 20°; whorls eight or nine (only five or six usually preserved), 
gently convex; sutures simple, deep; sutural angle 93°; surface crossed by very fine, slightly sigmoid strie. 
5 23 [i 
Length one inch two lines, proportional width at base ;%,, length of last whorl =, length of the penultimate =. 
Usually found in the state of casts, and may be distinguished from the casts of the M/urchisonia tor- 
quata (M°Coy), abounding in the same beds, by its more elongate form (smaller apical angle), less convex 
whorls, and the sharp simple sutural line. The last whorl near the mouth sometimes obscurely angulated. 
Position and Locality_Common in the Upper Ludlow micaceous quartzite of Horeb Chapel, Llandovery, 
S. Wales; ditto (tilestone), Benson Knot, Kendal, Westmoreland. 
TIOLOPELLA TENUICINCTA (M*Coy). Pl. 1. L. fig. 17. 
Ref—ld. M°Coy, Ann. Nat. Hist. 2nd Series, Vol. VIII. p. 408. 
Sp. Ch.—Very elongate, spiral angle 20°, whorls probably eight or nine, but only five or six usually pre- 
served, gently convex; sutures simple, deep; sutural angle 80°; surface girt with close, fine, sharp, subequal, 
spiral strize (about thirty-five in the space of one line on the basal whorls), crossed by a few obsolete, sig- 
moidally arched lines of growth. Length about eight lines, proportional width at base ,\,, length of last whorl 
=, length of penultimate whorl =. 
I imagine this may be the Scotch fossil referred by Mr Salter (Quart. Geol Journ. for Aug. 1851) to the 
Upper Ludlow Twrritella (Holopella) obsoleta of Sowerby, as it has very much the same size and shape, and the 
distinctive spiral lineation requires a good cross-light and some care to detect*, but with these, and a lens of low 
power, it may be always seen, even in the sandstone casts, and the species thus easily distinguished from that of 
the newer rocks. The sutures are also more oblique than in the H. obsoleta. The slight inequality of size of the 
strize seems in part subalternate, and in part irregular. 
* Since the above was in type Mr Salter shewed me the specimen alluded to by him, at the Jermyn Street Museum, 
and we found the striation in question, confirming the above surmise. 
