204 
CONCHIFERA 
Venus. 
The Corn brash, Scarborough. 
4. Pullastra virginea. —The Virgin Pullastra, pi. 
LXXXIII. fig. 1. 
P. virginea . Brown, Illust. Rec. Conch. Brit. p. 89, pi, 
36, fig. (5, and pi. 37, figs. 8, 9. 
Oblong-ovate; sub compressed; smooth and shining, with 
wide-set, shallow, concentric stria), here and there interrupted 
by a deeper one ; lunule lanceolate; margins smooth. 
The Pleistocene Marine Formation, Ayrshire, and the Red 
Crag, Sutton. 
5. Pullastra decussata.— Tho Decussated Pullastra, pi. 
LXXXIII. fig. 0. 
P. decussata. Brown, Illust. Rec. Conch. Brit. p. 88, pi. 37, 
figs. 5, 6. 
Transverse, inequilateral; anterior side shortest; sub-rhom- 
boidal; anterior side a little truncated ; whole surface covered 
with longitudinal and transverse stria), producing a beautiful 
and decussated appearance, which is stronger on tho anterior 
side; beaks obtuse, with a lanceolate lunule. 
The Pleistocene Marine Formation, Ayr and Paisley. 
6. Pullastra oblita. —The Forgotten Pullastra, pi. 
LXXXIII. fig. 5. 
P. oblita. Phillips, Geo. York, I. pi. 11, fig. 15. 
Transversely oblong-ovate ; anterior side acutely rounded ; 
posterior side slightly flattened and acuminated; beaks 
obtuse; surface with almost equidistant regular linos of 
growth. 
The Inferior Oolite, Blue Wick, Yorkshire. 
7. Pullastra recondita. —The Hidden Pullastra, pi. 
LXXXIII. fig. 11. 
P. recondita. Phillips, Geo. York, I. pi. 9, fig. 13. 
Transversely ovate ; both extremities rounded ; a central 
ridge from the beak to tho margin ; whole surface with nume¬ 
rous concentric furrows ; beaks small. 
Tho Great Oolite, Clough ton, Wyke and Brora. 
8. Pullastra elliptica. —Tho Elliptical Pullastra, pi. 
LXXXIII. fig. 12. 
P. elliptica. Phillips, Pal. Foss. p. 35, pi. 17, fig. 54. 
Regularly ovate, much compressed; beaks hardly protrud¬ 
ing ; surface smooth, with wide-set concentric stria). 
9. Pullastra antiqua. —The Ancient Pullastra, pi. 
LXXXII. fig. 10. 
P. antiqua. Soworby, Geo. Tr. 2d Scr. V. pi. 53, fig. 28. 
Phillips, Pal. Fos. pi. 17, fig. 55. 
Transversely oblong-ovate; moderately convex; anterior 
tide rounded ; posterior side slightly and obliquely truncated; 
beaks scarcely developed ; surface with regular wide-set con¬ 
centric strite. 
Tho Devonian Rocks, Pilton, Marwood, and Plymouth. 
10. Pullastra irus.— The Stone Pullastra, pi. LXXXIII. 
fig. 13. 
P. irus. Brown, Illust. Rec. Conch. Brit. p. 89, pi. 3G, 
fig. 9. Vcnirupus perforans , Turton, Biv. p. 29, pi. 2, figs. 
15-18. 
Transversely sub-ovate ; surface with concentric, membran¬ 
aceous, elevated, undulating ridges, reflected upwards, fre¬ 
quently interrupted ; the interstices with fine longitudinal 
striae. 
The Red Crag, Walton Naze. 
Genus XXIX.—VENUS.—Zinnaw. 
Shell smooth, equivalve, inequilateral, transverse, subglo- 
boso,or sub-oval; external surface sometimes rugose; margin 
close ; three divergent cardinal teeth in each valve, all approxi¬ 
mate ; umbones prominent for the most part, with a cordi- 
form depression immediately below them ; two lateral, remote, 
somewhat orbicular muscular impressions, united by a pallial 
impression, which is generally sinuated behind ; ligament ex¬ 
ternal, although sometimes almost hidden by the extension of 
the outer edge of tho shell. 
1. Venus submersa. —The Bulged Venus, pi. LXXIV. 
fig. 2. 
V. submersa . Sowerby Geo. Tr. 2d Ser. IV. p. 342, pi. 
17, fig. 4. 
Nearly orbicular; extremely tumid; beaks approximate : 
lunette obscure; hinge slope gently curved; posterior side a 
little truncated ; surface quite smooth. 
The Greensand, Blackdown. 
2. Venus sub-l.evis.— Tho Half-Smooth Venus, pi 
LXXXIV. fig. 8. 
V. sub-lceris. Sowerby, Geo. Tr. 2d Ser. p. 342, pi. 17, f. 5. 
Elliptical, compressed ; beaks pointed, situate near to one 
side ; lunette not sunk or defined ; surface smooth, with a few’ 
shallow, hardly impressed linos of growth. 
Tho Greensand, Blackdown. 
3. Venus immersa. —The Immersed Venus, pi. LXXXIV. 
fig. 9. 
V. immersa. Sowerby, Geo. Tr. 2d Ser. IV. p. 342, pi. 
17, fig. G. 
Transversely elliptical ; much compressed ; beaks consider¬ 
ably acute; lunette deeply suuk, its edge not defined; back 
and base elegantly curved; posterior side a little nanwed; 
anterior sido a little concave below the beaks ; surface smooth, 
with remote, nearly obsolete lines of growth. 
The Greensand, Blackdown and Lyme Regis. 
4. Venus ovalis.—T he Oval Venus, pi. LXXXIV. f. 1G. 
V. ovalis. Sowerby, VI. p. 129, pi. 5G7, figs. 1, 2. 
Transversely oval; convex; beaks well defined; lunette 
obscure, elongated, prominent, and smooth; surface with 
numerous very fino concentric stria). 
Tho Lower Greensand, Parham. 
5. Venus varicosa.—T ho Warted Venus, pi. LXXXIV 
fig. 17. 
V. varicosa. Sowerby, III. p. 173, pi. 296, figs. 1, 2. 
Sub-globose; beaks large, produced, and incurved; sides 
nearly alike; surface with shallow', concentric furrows, and 
two longitudinal varicose ridges within each valve. 
The Cornbrash, Felmersham, Bedfordshire. 
G. Venus rugosa.—T he Rough Venus, pi. LXXXIV. f. 5. 
V . rugosa . Brown, Illust. Recent Conch. Brit, and Ire¬ 
land, p. 90, pi. 36, fig. 14. 
Sub-triangularly sub-cordiform ; rather convex; lunette ob¬ 
long, heart-shaped; beaks considerably turned to one side ; 
surface with numerous rough concentric ridges; a hollow 
elongated space on tho cartilage hingo-lme ; margin blunt, 
and crenated internally. 
The Pleistocene Marine Formation, Dalmuir, on the Clyde, 
&c. 
