138 
MOLLUSCA. 
Terebratula. 
Deltoidal, gibbose; beak prominent; centre of the front 
elevated, with throe long plaits emanating near the beak ; 
sides with four or more plaits below the middle. 
Carboniferous Limestone, Winster and Ardconnaught, 
Ireland. 
81. Terebratula latissima.— The Very Broad Terebra- 
tula, pi. LYI. figs. 86, 87. 
T. lata . Sowerby, Y. p. 165, pi. 502, fig. 1 . 
Transversely elongated, convex ; larger valve the flattest, 
with a produced beak ; front elevated ; surface with forty regu¬ 
lar divergent narrow ribs, ton or twelvo of which are raised 
with the front. 
Upper Greensand, Warminster and Devizes ; Lower Green¬ 
sand, A then field and Parham. 
82. Terebratula depressa.— The Depressed Terebra¬ 
tula, pi. LYI. figs. 9, 10. 
T. depressa. Sowerby, Y. p. 165, pi. 502, fig. 2. 
Triangular, depressed; front elevated, with about eight 
plaits ; beaks produced; lateral angles rounded ; whole surface 
with about twenty regular divergent ribs. 
Upper Greensand, Islo of Wight and Blackdown, and Lower 
Greensand, Pulborough. 
83. Terebratula nuciformis. —The Nut-Shaped Tcre- 
bratula, pi. LYI.* fig. 13. 
T. nuciformis. Sowerby V. p. 166, pi. 502, fig. 3. 
Transversely elongated ; globose ; front elevated ; beak pro¬ 
duced ; surface with thirty rounded, regular, narrow, diver¬ 
gent ribs, many of which have a slight groove near the front, 
their edges plain and rounded. 
Upper Greensand, Rowde Hill, and Lower Greensand, 
Shanklin and Pulborough. 
84. Terebratula acuta.— Tho Acuto Terebratula, pi. 
LYI. fig. 82, 83. 
T. acuta. Sowerby, II. p. 115, pi. 150, fig. J, 2. Phillips, 
Geo. York. I. p. 134, pi. 13, fig. 25. 
Triangular, a little transverse; middle elevated, with one 
very large acutely angular plait; sides slightly rounded, with 
one largo and several small lateral plaits, on each seldom 
exceeding two, tho first large and sharp, extending nearly to 
the obtuse beak, the others merely undulations ,* front sinus 
almost an equilateral triangle. 
Inferior Oolite, 11 minster and Cheltenham, and the Lias, 
Wilton Castle, and Bilsdale. 
85. Terebratula acuta-plicata. —The Acute-Plaited 
Terebratula, pi. LY/ fig. 98, 99. 
T. acuta. Sowerby, Y. p. 166, pi. 502, fig. 4. 
Transversely elongated ; somewhat pocket-shaped ; gibboso ; 
beak a little produced, but small, and slightly curved ; front 
elevated, with six plaits, the lateral ones bciug largest, tho 
whole surface with many sharp plaits. 
Inferior Oolite, Bilsdale and Cheltenham. 
86. Terebratula plicatella. —Tho Folded Terebratula, 
pi. LYI. fig. 68, 69. 
T. plicatella . Sowerby, Y. pi. 503, fig. 1. 
Elongated, somewhat quadrangular, inflated ; beak small, 
incurved, with an ovate concave depression on each side under 
it; surface provided with about forty rounded plaits, some¬ 
times furcated near the beaks, ten or twelve of which are 
gradually elevated with the front; sides descending in a rather 
straight line from the umbones. 
Found very sparingly in the Inferior Oolite, Bridport. 
87. Terebratula serrata. —Tho Serrated Terebratula^ 
pi. LYI.* fig. 24, 25 # 
T. serrata. Sowerby, Y.. p. 168, pi. 503, fig. 2. 
Suborbicular, subtriangular, inflated, with an obtuse margin ; 
beak small, incurved, with a large, concave, ovate space on 
each side beneath it; surface with about eleven sharp plaits, of 
which five are somewhat elevated in front. 
Lias, Lyme Regis. 
88. Terebratula truncata. —The Truncated Terebra¬ 
tula, pi. LYI. fig. 20, 21. 
T. truncata. Sowerby, VI. p. 71, pi. 531, fig. 3. 
Slightly ovate; hinge lino nearly straight, and extending 
the whole width of the valves ; larger valve subconical, with a 
large, short, straight beak, flattened in front, and provided with 
an ample round aperature ; surface with about twenty sharp, 
sometimes furcated plaits; front with from two to five ele¬ 
vated ones; lesser valve much flattened. 
Lower Greensand, Farringdon. 
89. Terebratula mantelliana. —Mantel l's Terebratula, 
pi. LYI. fig. 53, 54. 
T. Mantelliana . Sowerby, YI. p. 72, pi. 537, fig. 5. 
Transversely obovato, and inflated, with a small produced 
slightly incurved beak ; with about sixteen large, sharp, simple 
plaits, from four to six of which arc considerably elovatod in front. 
Chalk Marl, Hamsey. 
90. Terebratula Gibbsiana. — Gibb’s Terebratula, 
pi. LYI. fig. 66, 67. 
T. Gibbsiana. Sowerby, YI. p. 72, pi. 537, fig. 4. 
Suborbicular, somewhat triangular, and inflated ; beak small, 
acute, and incurved; lesser valve more convex than tho other; 
surface with numerous rounded simple plaits; front greatly 
elevated, with about ten or twelve flattened plaits. 
Lower Greensand, Folkstoue, Sandgate, Boughton, and Isle 
of Wight. 
91. Terebratula inconsAns. —Tho Inconstant Terebra¬ 
tula, pi. LYI. fig. 11, 12, 13. 
T. inconstans. Sowerby, III. p. 137, pi. 277, fig. 3, 4. 
Phillips, Geo. York. I. p. 94, pi. 2, fig. 24. 
Globular, beak small, acute, and incurved; one-half of the 
margin turned up and the other down, but sometimes in the 
right, and at others the left; a medial depression in tho larger 
valve; surface with from twenty-four to twenty-six angular 
plaits, half of them on one side elevated. 
Speeton Clay, Speeton and Knapton, and tho Oxford Clay, 
Heddington and Osmington. 
92. Terebratula obliqua. —The Oblique Terebratula, 
pi. LYI * fig. 8. 
T. obliqua. Sowerby, III. p. 137, pi. 277, fig. 2. 
Subcompressed aud transversely obovate ; beak produced and 
slightly incurved; surface with about fifteen angular plaits, 
on one side five, central ones elevated, and turned downwards. 
Upper Chalk, Norwich and Ramsgate. 
93. Terebratula Mantle. —MantsTerebratula, pi.LYI/ 
fig. 13. 
• T. Mantxce. Sowerby. III. p. 137, pi. 277, fig- L 
Subcoinpressed and subtrigonal, with the beak prominent 
and slightly incurved, and forming nearly an equilateral tri¬ 
angle ; front rounded; surface with about sixteon angular 
plaits, half of them on one side elevated ; upper valve convex. 
