Spirifer. 
MOLLUSCA. SPIRIFERA. 
375 
in the sinus, which is smooth and angular, instead of being rounded and stri- 
ated.” — Mart. Derb. t. xxxvi. f. 2. — In Carhoniferom Limestone^ Derbyshire. 
4. S. oblatus. — Gibbose, transversely obovate, smooth, with an obtuse, 
rather square, elevation along the middle ; beaks approximated. — Sower. Min. 
Conch, t. cclxviii.— Cariowi/erows Limestone. 
5. S. glaber . — Nearly twice as wide as long, generally sharp-edged. — Mart. 
Derb. t. xlviii, f. 9-10. — Sower. Min. Conch, cclxix., two upper fig. — In Car- 
boniferous Limestone : — probably identical with the last. 
6. S. obtusus — Gibbose, transversely oval, very obscurely striated, with an 
obtuse, rounded elevation along the middle ; beaks rather distant. — Sower. 
Min. Conch, t. cclxix., two lower figures.— In Carboniferous Limestone. 
7* S. striatus. — Hinge-depression extending the whole breadth of the shell ; 
longitudinal ribs numerous, unequal, branched, mesial ridge rounded.— Ano- 
mites striatis. Mart. Derb. t. xxiii. — Spir. striatus. Sower. Min. Conch, 
t. cclxx., and S. rotundatus, ib. t. cccclxi. f. 1 -..-Carboniferous Limestone. 
8. S. pinguis. — Gibbose, transversely obovate, with a straight back, longi- 
tudinally sulcated, elevated in the middle ; sulci eight or nine on each side, 
and one in the centre of the elevation — Sower. Min. Conch, t. cclxxi. — Car- 
boniferous Limestone. 
9. S. acutus — Valves convex, semicircular, with deep equal ribs, the me- 
sial edge and furrow smooth ; hinge-space short ; beak of the perforated 
valve prominent, incurved.— An omites acutus, Mart. Pet. Derb. t. xlix. f. 15, 
16. Spirifer minimus. Sower. Min. Conch, t. ccclxxvii. f. 1 . — Carboniferous 
Limestone. 
10. S. Suborbicular, gibbose, with one large, rounded, elevated 
fold in the middle, and four smaller ones on each side — Sower. Min. Conch, 
t. ccclxxvii. f. 2. In Lias. 
11. ^.lineatus. — Gibbose, covered with numerous diverging sharp strije; 
front semicircular, elevated in the middle ; from the elevation of the front 
a convex band proceeds to the beak ; hinge-line long and straight ; beaks 
rather distant — Sower. Min. Conch, t. ccccxcii. f. 1, 2. — In Carbmiferous 
Limestone. 
12. S. attenuatus: — Convex, covered with numerous linear furrows, which 
increase in number towards the margin ; front rounded, elevated in the mid- 
dle, from each side of the elevation a deep furrow proceeds to the beak ; 
sides produced, pointed ; hinge-line long, straight ; space between the beaks 
flat, with nearly parallel edges — Sower. Min. Conch, t. ccccxciii. f. 3, 4, 5.— 
In Carboniferous Limestone. 
13. S. bisulcatus — Semicircular, gibbose, longitudinally sulcated, elevated in 
the middle, a deep furrow on each side the elevation ; hinge-line long, 
straight ; beaks close. — Sower. Min. Conch, t. ccccxciv — Carboniferous Lime- 
strnie. 
14. S. distans. — Semicircular, gibbose sides sulcated longitudinally ; front 
elevated, elevation extending to the beaks, concave along the middle ; beaks 
incurved, distant, the space between them curved, triangular.— Min. 
Conch, t. ccccxciv. f. ^.—Carboniferous Limestone. 
15. S. Transversely oval, with numerous longitudinal striae 
and distant marks of growth ; perforated valve slightly convex towards the 
beaks, depressed towards the margin ; the other valve more convex ; mar- 
