CONCHIFERA. 
Sphenia. 
932 
Cardita (?) obtusa . Sowerby, III. p. 219, pi. 197, fig. 2. 
Gibbose, transversely obovate ; length but little less than 
the width, and somewhat recurved ; anterior side longest, ob¬ 
tuse, and plain, with from seven to ten longitudinal, nearly 
equal, tnberculated ridges. 
Inferior Oolite, Dundry, and Cotswold Hills. 
4. Pholadomya Li rata. —The Ridged Pholadomya, pi. 
XCV. fig. 9. 
Cardita (?) lirata . Sowerby, III. p. 220, pi. 197, fig. 3. 
Gibbose, transversely oblong, width nearly double its length ; 
posterior side convex, provided with a large ridge, and 
two or three tuberculated ridges; whole surface with nine or 
ten tuberculated ridges, and that separating the posterior side 
the highest of the whole. 
Inferior Oolite, Cotswold Hills ; the Lias, at Bath and 
Peterborough, and the Fullers Ea v th, Alford, Wiltshire. 
5. Pholadomya deltoidea. —The Lurking Pholadomya, 
pi. XCV. fig. 10. 
Cardita (?) delloidea. Sowerby, II. p. 220. 
Very gibbose, obtusely triangular, with eight or nine longi¬ 
tudinal, rugged, very irregularly tuberculated ridges, which 
are longest near the posterior end ; anterior side pointed; 
beaks rather prominent. 
Coral Rug, lleddington and Malton. 
6. Pholadomya decussata.— The Decussated Pholadomya, 
pi. XCVI. fig. 5. 
Cardinal dec ns sal am. Sowerby, VI. p. 99, pi. 552, fig. 1. 
Cord.i<trin; posterior side with abroad area elevated in the 
middle, bounded by an obtuse keel; length and breadth nearly 
equal ; anterior side more prominent than the posterior ; 
beaks incurved; surface with strong longitudinal ribs, and 
decussated by irregular transverse ones, becoming closer as 
they approach the base of the valves. 
Chalk Marl, Ilamsey, Sussex, and Speeton. 
7. Pholadomya ambigua. —The Ambiguous Pholadomya, 
pi. XCV. fig. 4. 
Lutraria ambigua. Sowerby, III. p. 48, pi. 227. 
Transversely elongated, gibbose, a little recurved, gaping 
anteriorly; surface with several oblique divergent furrows. 
This species is variable in width, some specimens being nearly ob¬ 
ovate and teeth stronger, and, in general, knotted ribs. 
The Inferior Oolite, Cotswold Hills, and the Lias, Weston, 
Yorkshire. 
8. Pholadomya fidicula. —The Harp Pholadomya, pi. 
XCVI. fig. 2. 
Lutraria. lirata. Sowerby, III. p. 47, pi. 225. 
Transversely elongated, its width twice and a half its 
length ; gibbose, recurved ; surface with numerous obliquely 
longitudinal ridges; the anterior side almost smooth, and 
somewhat compressed. 
The Inferior Oolite, Cotswold, and the Blue Wick. 
9. Pholadomya ovalis. —The Oval Pholadomya, pi. XCVI. 
fig. 4. 
Lutraria ovalis. Sowerby, III. p. 47, pi. 226. 
Transversely elongated, elliptical and mostly straight, some¬ 
what convex; curvature of front and back nearly equal; sides 
rounded and slightly gaping, the posterior one considerablv 
the smallest, with only one furrow on it; surface with about 
nine divergent longitudinal ridges. 
The Portland Stone, Felmersham, Portland, and the Corn- 
brash, Scarborough. 
10. Pholadomya angustata. —The Narrow Pholadomya, 
pi. XCVI. fig. 8. 
Lutraria angustata. Sowerby, IV. p. 29, pi. 327. 
Transversely elongated, gibbose, anterior side rather com¬ 
pressed ; posterior side rounded, and extends a little way from 
the beaks; surface with about twelve oblique acute ribs, which, 
as well as the intervening furrows, are decussated by numerous 
irregular transverse striae; substance of the shell thin, and in 
consequence the ribs are uoarly as conspicuous internally as 
without. 
The Inferior Oolke, Dundry. 
11. Pholadomya Murchisoni. —Murchison’s Pholadomya, 
pi. XCVI. fig. 6. 
P. Murchisoni. Sowerbv, VI. p. 87, pi. 545, fig. 1. 
Oval, beaks large ; posterior side short, provided with six or 
seven elevated, obtusely round, divergent, longitudinal ribs, 
intersected by strong, undulating, wide-set furrows, giving the 
ribs a knotted appearance. 
From the Roof of the Coal Workings, Brora. 
12. Pholadomya nana. —The Dwarf Pholadomya, pi. 
XCV. fig. 2. 
P. nana. Phillips, Geo. York, 1. pi. 9, fig. 7. 
Transversely elongated ; posterior side nearly straight ; 
beaks large and obtuse ; anterior side rounded ; surface with 
coucentric lines of growth, and a fow nearly obsolete radiating 
furrows towards the base, in the middle of the valves ; basal 
line nearly straight. 
The Great Oolite, White Nab, Yorkshire. 
13. Pholadomya obsoleta. —Tho Obsolete Pholadomya, 
pi. XCY. fig. 3. 
P. obsoleta. Phillips, Geo. York, I pi. 5, fig. 24. 
Transversely elongated; beaks obtuse, situate towards the 
posterior side, which is short and a little narrowed; anterior 
sido somewhat wider and rounded ; surface with concentric 
furrows, and four radiating narrow furrows from the beaks to 
tho basal lino. 
The Great Oolite, Brandsby. 
14. Pholadomya Piiillipsii.— Phillip’s Pholadomya, pi. 
XCV. fig. ll. 
P. Murchesoni . Phillips, Geo. York, I. p. 27, fig. 9. 
Transversely oval, much inflated; beaks produced, conside¬ 
rably incurved, situato nearest the posterior sides, which is 
shortest, and with long, longitudinal, narrow ribs, which 
radiate from the beaks to the basal margin, projecting a little 
beyond it, giving a scolloped aspect, and occupying about half 
the valve; anterior to these, two radiating narrow furrows; 
the anterior sido rounded, and slightly contracted below. 
The Cornbrash, Scarborough. 
15. Pholadomya compuessa. —The Compressed Phola¬ 
domya, pi. XCV. fig. 5. 
Transversely elongated, somewhat heart-shaped, oblique, 
compressed ; beaks largo, prominent, and quite approximating; 
surface with six large distant radiating ribs, leaving a large 
bare space between them and the beaks. 
Tho Great Oolite, Kettering, Northamptonshire. 
16. Pholadomya cuneata. —The Wedge-Shaped Phola¬ 
domya, pi. XCV. fig. 7. 
