290 BRITISH PALASOZOIC FOSSILS. [GasTEROPODA. 
Genus. CAPULUS (Mont/,) 
_ Ref. and Syn. = Pileopsis Lam. = Hipponyx Defr. = Acroculia Phill. 
Gen. Char.—Shell wide, cap-shaped, apex obliquely inclined backwards, and inrolled towards the left side : 
aperture broad, oval, with the edge irregularly sinuated; muscular impression, horse-shoe-shaped, open in 
front; animal as in the family characters. 
Those species which secrete a round calcareous disk for the foot have been considered bivalves, and 
named Hipponyx by Defrance ; but even the common Patel/a does the same thing occasionally, as may be 
well seen about Plymouth. 
Recent in all latitudes, remaining permanently fixed to one spot of rock or shell during its life-time, 
also tertiary, cretaceous, oolitic, and palzeozoic. 
Caputus? EvompnHatoipes (M*Coy). Pl. 1. K. fig. 39. 
Sp. Ch.—Depressed, spirally inrolled, whorls rounded ; spire depressed, of one and half turns; surface 
apparently smooth, or faintly marked by broadly undulated wrinkles of growth (indicating the waving of the 
right lip). Diameter one inch, proportional diameter of body-whorl ;j;, height =. 
This curious species is so much depressed, that were it not for the small size of the spire, and the un- 
dulation of the lip, as revealed by the flexuous lines of growth, it might be taken for a Huomphalus. I at 
one time thought it might be desirable to form a particular genus for these palzeozoic species, such as the 
Nerita Haliotis (Sow.), Pileopsis neritoides (Phill.), &c. having the form of Nerita, but an undulating lip and 
lines of growth; on examining carefully the recent Pileopsis intortus and allied species, I found so gradual 
a passage from them to the ordinary cap-shaped forms, that I prefer leaving them all together for the present. 
None of my specimens of that type of shells shew the mouth clearly, so that it is possible they may want 
the inner lip, in which case the genus would be a very good one, and only found, I believe, in the older 
rocks. 
Position and Locality.—Rare in the Lower Ludlow limestone at Green Quarry, Leintwardine, Shropshire. 
Explanation of Figure —P|. 1. K. fig. 39, natural size. 
CapuLus? Harioris (Sow. Sp.) 
Syn.— Nerita Haliotis Sil. Syst. t. 12. f. 16. 
Sp. Ch.—Mouth very wide, nearly orbicular, outer lip deeply and irregularly undulated ; spire neriti- 
form of two spirally inrolled, lateral, convex, whorls, scarcely rising above the level of the body whorl; sur- 
face covered with minute, slightly flexuous spiral strise, which near the spire, are so close and fine as to be 
almost invisible, but towards the base (or anterior part of the body whorl) they become a little coarser, and 
some at intervals are much larger than the intervening ones, all crossed by the waving lines of growth. 
Width one inch three lines; proportional length 4; width of body whorl 5. 
In old individuals one or two interrupted spiral wrinkles often occur on the upper part of the body 
whorl. In the above-quoted figure the lines of growth are not sufficiently undulated to express the general 
character, and the finer spiral striz are not seen. 
Position and Locality—Not rare in the Wenlock limestone of Ledbury, Herefordshire. 
14th Family. HALIOTID. 
Shell varying in form from elongate conic to depressed and ear-shaped ; aperture wide, indented by the last 
whorl, nacreous, and (with one exception) having either a deep slit or row of foramina in the thin, simple, outer 
lip, leaving a band which extends back along the whorls of the spire: (animal usually too large for the shell ; 
foot wide, oval; operculum rudimentary or none; eyes on long pedicles at the base of the tentacles ; mantle 
