Spirifer. 
MOLLUSCA. 
115 
83. Spirifer disjunctus —The Disjoined Spirifer, pi. 
LII.* fig. 48. 
Spirifera disjuncta. Sowerby, Geo. Trans. V. 2 nd series, 
pi. 53, fig. 8 , and pi. 54, fig. 12, 13. 
Very convex, semicircular; base emarginate; upper valve 
with about twelve divergent, pretty strong ribs, raised in front, 
producing a rounded elevation ; lower valve with numerous, 
rounded ribs, about twenty-five on each side of the mesial one; 
hinge area broad, curved, with nearly parallel edges; beaks 
remote. 
Differs from S. bisulcata , pi. L. fig. 21, 22, in being less convex, and 
in its more numerous striae, with its binge line broader. 
Found in the Devonian Shale at Petherwin and Barnstaple. 
84. Spirifer partitus. —The Divided Spirifer, pi. LII.* 
fig. 50, 51. 
Spirifera partita. Portlock, Geo. Rep. p. 567, pi. 38, 
fig. 3. 
Round; lower valve with a deep sinus, extending to the base; 
the opposite valve with a corresponding rib ; the furrows and 
ribs, between which and the sides are strongly marked, vary in 
number from three to six. 
Approaches in form to S. speciosus, fig. 24, 25. 
Found in the Carboniferous Limestone at Kildress, Ireland. 
85. Spirifer simplex. —The Simple Spirifer, pi. LII.* 
fig. 49 and 58. 
Spirifer simplex . Phillips, Pal. Fos. p. 71, pi. 29, fig- 
124. 
Pyramidal; cardinal area very large, triangular; mesial rib 
with obtuse borders; triangular foramen narrow, reaching to the 
point of the beak in the larger valve; smaller valve convex; 
destitute of ribs or furrows. 
Found in the Devonian Shale at Plymouth and Newton, 
South Devon. 
86 . Spirifer l/evis. — The Smooth Spirifer, pi. LII.* 
fig. 52. 
Spirifer Icevis? Sowerby, Sil. Syst. p. 638, pi. 21, fig. 12. 
Transversely elongated, semicircular, smooth, compressed; a 
slight obsolete rib along the middle; beaks of umbones pro¬ 
minent, divided by a narrow area, with parallel edges. Length 
eight lines; breadth double its length. 
Found in the Lower Silurian Rocks at Noeth-grag; Land- 
overy; May Hill, Gloucestershire; Gullet Wood, Estnor Park, 
and Hope Hill, Salop. 
87. Spirifer calcaratus, —The Spur Spirifer, pi. LII.* 
fig. 53. 
Spirifer calcaratus. Sowerby, Geo. Trans. V. 2 nd scries, pi. 
53, fig. 7- Phillips, Pal. Fos. pi. 29, fig- 128. 
Transversely elongate, semicircular; sides very convex, pro¬ 
duced, cuspidate, smooth, with longitudinal sulci; front hardly 
elevated; with numerous rounded ribs, about nine on the front 
circumscribed by two deep furrows; cardinal area very narrow. 
Width double its length. 
Distinguished from S. attenuate, pi. L. fig. 25, 26, by the sudden 
contraction of the sides, and the very slight elevation in front. 
88 . Spirifer Urii.—U re’s Spirifer, pi. LII.* fig. 54, 55. 
Spirifer Urii. Fleming, Brit. An. p. 313. Ure, Ruth, and 
Kil. p. 313, pi. 14, fig. 12 . Spirifer Unguiculus , Phillips, Pal. 
Fos. p. 69, pi. 28, fig. 119- Atrypa Unguiculus , Sowerby, 
Geo. Trans. V. 2nd series, pi. 54, fig. 8 . 
Hemispherical, somewhat wider than long, smooth, with the 
beak inflated; base emarginate; lower valve very convex, with 
its beak channelled; upper valve compressed, with a central im¬ 
pressed line. 
Found in the Devonian Shale at Petherwin, near Barnstaple, 
Pilton, Brushford, and Rutherglen, Renfrewshire. 
89- Spirifer nudus —The Naked Spirifer, pi. LII.* 
fig. 56. 
Spirifer nuda. Sowerby, Geo. Trans. V. 2nd series, pi. 57, 
fig* 8. 
Semicircular, with the beaks prominent and smooth; a mesial 
rib, with a furrow on each side; margin obtuse. 
Found in the Devonian Shale at Plymouth. 
90. Spirifer plicatus. —The Plaited Spirifer, pi. LII.* 
fig- 57. 
Spirifer plicatus. Sowerby, Sil. Syst. p. 638, pi. 21, fig. 6. 
Transversely elongated, semicircular, convex; with numerous, 
radiating, sharp plaits, which are narrow above, and become 
wider towards the base; beaks contiguous; cardinal area narrow ; 
hinge line nearly double the length of the valves. Length 
eleven lines; width one inch and seven lines. 
Found in the Lower Silurian Rocks at Goleugoed, Llan¬ 
dovery. 
Genus IV.—GYPIDIUM.— Sowerby. 
Shell inequilateral, inequivalvc; the larger valve with 
an incurved umbo, remote from the hinge; the larger 
valve divided by a central suptum into two parts; the 
other by two parallel, approximate septa into three un¬ 
equal parts; umbones imperforate, and incurved. 
1. Gyiudium Aylesfordii —Aylesford’s Gypidium, pi. 
XLIX. fig. 31, 32. 
Pentamerus Aylesfordii. Sowerby, I. p. 75,* pi. 29. Fle¬ 
ming, p. 378. 
Almost orbicular; with rather strong, longitudinal ribs, the 
intervening furrows narrow below; larger valve more inflated 
than the other, with a prominent, greatly incurved beak. 
In the young condition the umbones are not so different in size, as in 
the adult, and they are proportionally more approximate. 
Carboniferous Limestone, Colebrookdale; and in the Ames- 
try Limestone, Croft Ambery Park, and Yeo-edge. 
2. Gypidium Knightii. —Knight’s Gypidium, pi. XLIX. 
fig. 2. 
Pentamerus Knightii. Sowerby, I. p. 73,* pi. 28, upper 
figure. Fleming, p. 378. Murchison; Sil. Syst. p. 615, pi. 6, 
fig. 8, «, h , c. 
Suborbicular; one valve small, the other large, with a long, 
considerably incurved beak; surface with numerous, strong, 
rounded, longitudinal ribs, crossed by inequidistant lines of 
growth ; cardinal area smooth, and triangular. 
The Amestry Limestone at View Edge, Ludlow; Amestrv ; 
Sedgeley, near Dudley; Dowton-on-the-Rock, and Yeo-edge. 
3. Gypidium l.-evis. —The Smooth Gypidium, pi. XLIX. 
fig. 39, 40, 41, 42, 43. 
Pentamerus Icevis. Sowerby, I. p- 76,* pi. 28, right hand 
figure. Ib. Sil. Syst. p. 641, pi. 19, fig. 9. Fleming, p. 378. 
