Catillus, 
CONCHIFERA. 
165 
times its length ; depressed, slightly curved, and smooth ; ante¬ 
rior extremity truncated, open ; teeth of the hinge variously 
disposed, irregular, and linear, those of the exterior extremity 
are most produced, and placed perpendicular to the hinge- 
lino ; the others lie in the same direction with it, and are fre¬ 
quently curved, with about four depressions. 
The Lower Greensand, Sussex; Isle of Wight; Dorset and 
Devonshires. 
2. Gervillta acuta ?—The Acute Gervillia, pi. LX IX. f 5. 
G. acuta . Sowerby, VI. p. 15, pi. 510, fig. 5. 
Ovate and lanceolate, its width four times its length ; ob¬ 
lique, narrow, somewhat depressed, and a little curved; sub¬ 
stance of the shell very thin ; anterior portion greatly attenu¬ 
ated, the opposite extremity rounded; teeth of the hinge 
variously disposed. 
In the Great Oolite, Collyweston. 
3. Gervillia aviculoides. —The Birds-Wing Gervillia, 
pi. LXIX. figs. 7, 8, 9. 
G. aviculoides. Sowerby, VI. p. 16, pi. 511. Perna avi¬ 
culoides . Ib. I. p. 147, pi. G6. 
Obliquely ovate, and lance-shaped, somewhat curved, with 
both extremities acute; hinge-line occupying nearly half the 
length of the shell; teeth few, all similarly disposed. 
Greensand, Blackdown and Lyme Regis ; Lower Green¬ 
sand, Sandgate; the Portland Sand, Langcombe; and the 
Oxford Clay, Osmington and Up ware. 
4. Gervillia lanceolata. —The Lance-shaped Gervillia, 
pi. LXIX. fig. 4. 
G. lanceolata. Goldfuss, p. 123, pi. 115, fig. 9. G . acuta . 
Phillips, Geo. York, I. pi. 9, fig. 36. 
Much elongated transversely, its breadth being five times its 
length ; the hinge-line long, nearly half the width of the shell, 
nearly straight and oblique, tapering to a point, the opposite 
side a little narrowed from the hinge, with a rounded, blunt 
termination ; surface nearly smooth, with a few nearly regu¬ 
lar, faint lines of growth. 
The Great Oolite, Colly weston, Brandsby, and Clough ton. 
5. Gervillia inconspicua. —The Inconspicuous Gervillia. 
G. inconspicua. Phillips, Geo. York,II. p. 212, pi. LXI.** 
fig. 30. 
Transversely elongated ; hiugo-linge extending the whole 
length of the valve; anterior sido short, rounded; posterior 
sido truncated ; surface with concentric wrinkles. 
Carboniferous Limestone, Castleton, Derbyshire. 
6. Gervillia laminosa.— The Laminated Gervillia, pi. 
LXVII. figs. 10, 16. 
G. laminosa. Phillips, Geo. York, II. p. 212, pi. 6, fig. 10. 
Very oblique inflated hinge-line, extending the whole length 
of tlio shell, with auriform processes on both sides of the beaks, 
the anterior one short and blunt; the posterior lengthened and 
acute; surface smooth, with concentric lines of growth ; base 
rounded. 
Fig. 16 is a cast of the inside. 
The Carboniferous Limestone, Bolland, Colsterdale. 
7. Gervillia minor.— Tho Small Gervillia,pi. LXI**f.3l. 
G. minor. Brown, Trans. Manchester Geo. Soc. I. p. 227, 
pi. 7, fig. 70. 
Very oblique; umbones flat, placed much to one sido; 
hinge-line long, straight; surface with numerous concentric, 
strong, rude wrinkles, with lesser intermediate ones. Length 
three-eighths of an inch, breadth three-fourths of an inch. 
Carboniferous Limestone Shale, High-Green Wood, Vale 
of Todmorden. 
8. Gervillia squamosa. —The Scaly Gervillia, pi. LXVII. 
fig. 18. 
G. squamosa. Phillips, Geo. York, II. p- 212, pi. G, fig. 9. 
Greatly oblique; binge-line nearly straight; one ear large, 
the othor small; posterior side ridged ; surface with scaly 
strips. 
The Carboniferous Limestone, Bolland. 
9. Gervillia lata. —The Broad Gervillia, pi. LXIX. 
figs. 1, 2. 
G. lata . Phillips Geo. York, I. pi. 11, fig. 1G. 
Obliquely transverse, much inflated, binge-line long, oblique, 
anterior side short, posterior side very large, beaks obtuse; 
surface smooth, with many equidistant concentric lines of 
growth. 
The Inferior Oolite and Blue Wick, Glaizc Dale. 
G ENUS XXVIIIC REN ATU LA. — Lamarck. 
Shell sub-oquivalve, compressed, inequilateral, oblique; 
somewhat distorted and lamellar; hinge-line lateral, linear, 
nearly straight, marginal, and internally crenulated ; the cre- 
nuhe formed in a continuous series along the hinge, each of 
them presenting a small rounded callosity, and excavated for 
tho reception of part of the cartilage, the intervening ridges 
covered with a true ligament ; muscular impressions almost 
obsolete, of an oblong form, and situate near the anterior mar¬ 
gin of tho pearlaceous substance. 
1. Crenatula vhntrigosa. —The Bellied Crenatula, pi. 
LXI.*** fig. 4. 
C. ventricosa. Sowerby, V. p. G4, pi. 443. 
Ovate, elongated, gibbose, ventricoso, and carinated; 
hinge-line short, posterior side much compressed, with its 
edges a little produced, but not lobate; front and anterior 
side rounded ; inside pearlaceous. 
In tho Lias, Bosworth, Leicestershire, Yorkshire, and Vale 
of Gloucester. 
2. Crenatula Listeri. —Listers Crenatula, pi. LXI.*** 
fig. 5. 
C. Listeri. Parkinson, Org. Rem. III. p. 220, pi. 15, f. 5. 
Elongated; hinge-line oblique; crenulations large; valves 
narrow above and wide below. 
Tho Great Oolite, Shotover. 
3. Crenatula product a. —The Produced Crenatula, pi. 
LXI.*** fig. G. 
C. producta. Parkinson, Org. Rem. III. p. 221, pi. 15, 
figs. G, 7- 
Much elongated ; hinge-line considerably oblique, with four 
large crenulations; beaks rather prominent, and a little turned 
to one side; basal margins of the valves much produced, and 
extending considerably below the body of the shell ; external 
surface with concentric lamina?. 
The Oolite, Shefford, Bedfordshire. 
Genus XXIX.—CATILLUS.— Brongniart. 
Shell thick, inequivalve, inequilateral; triangular, deep, 
