PLATE LYI. 
I. 2. Terebratula Nucula. {Kernel Terebratula.) Globose, trilobate; lower valve flattened; beak small, adpressed; with about fifteen 
sharp plaits. Diameter, J in. 
3,4. T. Brevirostra. ( Short-Beal:ed Terebratula.) Transversely elliptical; valves convex, equal; beaks large, short; with about twenty- 
five plaits. Length, J in.; breadth, J in. 
5, 6. T. Ferita. (- Terebratula.) Sub-triangular; beak long, straight, acute; lateral angles truncated; with a few, large ribs, 
transversely striated ; hinge-line short, straight. 
7,8. T. Interplicata. (Interplaited Terebratula.) Transversely obovate; valves equal, convex; beaks short; with many plaits ; sides, near 
beaks smooth, with prominent edges. Length aud breadth, J in.; depth, } in. 
9, 10. T. Depressa. ( Depressed Terebratula .) Triangular, depressed; front elevated, with about eight plaits ; beaks produced; lateral 
angles rounded; with about twenty, divergent ribs. 
II, 12, 13. T. Inconstans. (Ineomtant Terebratula.) Globular; beak small, acute, incurved; one half of margin turned up, the other 
down ; medial depression in larger valve ; with twenty-four to twenty-six angular plaits. 
14, 15. T. Angularis. (Angular Terebratula.) Pentagonal convex ; beak prominent; front, with three or four plaits ; margin compressed ; 
with deep, angular sulcus from centre of lower valve. 
16,17. T. Radialis. (Radiating Terebratula.) Orbicular; without mesial fold ; beak elevated, straight; with many, radiating ribs. 
15. T. Pusilla. hSfendtT Terebratula.) Globose ; with about fourteen, sharp plaits, four elevated at base. Diameter, J in. 
19. T. Lseviuseula. ( Very Smooth Terebratula.) Rliomboidal, convex, smooth ; base rounded ; sides angular. Diameter, J in. 
20,21. T. Truneata. (Truncated Terebratula.) Ovate; hinge-line straight; larger valve sub-conical, with large, short, straight beak, with 
ample, rounded aperture ; with about twenty, sometimes furcated plaits; smaller valve much flattened. 
22,23. T. Proboscidaiis. (Trunked Terebratula.) Elongated; beak prominent; front margin broad, protruding; with many, equal strioe. 
24, 25. T. Quadrata. ( Square-Shaped Terebratula.) V. Plate LY. - , Fig. 42. 
26. T. Borealis. ( Northern Terebratula.) Obovate, gibbose, trilobate; with about sixteen, acute, longitudinal plaits; beak small, acute, 
incurved. Length, 4 in.; breadth, jj in. 
27,28. T. Subplicata. (Half-plaited Terebratula.) Transversely ovate; gibbose; beak large; base parallel; both valves, with eight or nine 
large, longitudinal ribs. 
29, T. Tripartita. (Three-parted Terebratula.) Transversely oval, convex; with fifteen to twenty rough plates, often furcated; centre 
elevated.^ Length, J in.; breadth, 1J in. 
30, o0. T. Platyloba. (Flat-lobed Terebratula.) Transversely ovate, compressed; umbo obtuse; base, with seven or eight obtuse ridges; 
sides, with one or two plaits on edges. 
31, 32. T. Bidentata. (Two-toothed Terebratula.) Triangular, smooth, depressed; acutely plaited. Length and breadth, J in. 
33,34. T. Pentagona. (Pentagonal Terebratula.) Pentagonal, depressed; beak minute; tribolate; with about twenty five plaits. Length 
and breadth, J in. 
35. T. Pulchra. (Beautiful Terebratula.) Globose, triangular ; beak small, produced; trilobate; with about twenty plaits. Diameter, Jin. 
Unguis. (Cloven Terebratula.) Orbicular, inflated; beak incurved ; with about twelve, sharp plaits. Length and breadth, J in. 
37. T. Neglecta. (Neglected Terebratula.) Orbicular, convex ; beaks small; with seventeen, acute plaits. 
38, 39, 40, 55, 56. T. RenifoPniis. (Kidney -shaped Terebratula.) Reniform, bilobate, inflated; centre with three or four longitudinal ridges 
ending in acute plaits ; sides inflated. 
41, 42. T. Hemisphserica. (Hemispherical Terebratula.) Hemispherical; beak produced, incurved; smaller valve flattish; with manv. 
longitudinal ribs; margin toothed. 
43,44. T. Rigida. (Rigid Terebratula.) Orbicular; beak small ; smaller valve flattish ; larger valve convex; with many plaits; front even. 
f 6 * T * Tetrahedra. (Four-sided Terebratula.) V. Plate LV.*, Fig. 85. 
47,48,49. T. Fupcata. (Forked Terebratula.) Orbicular, smooth; one beak greatly curved ; interior, with several sulci and furcate channel 
m centre. Diameter, 4 in. 
... PUcatilis. (Fine-plaited Terebratula.) Gibbose, transversely obovate ; beaks short, incurved; larger valve inflated; centre 
with ^twelve, obtuse plaits, and fifteen or more on each side. 
jjjj* T. Mantelliana. (MantelVs Terebratula.) Transversely obovate, inflated ; beak small, incurved; with about sixteen, large, simple plaits. 
*>7. T. Pleurodon. (Side-toothed Terebratula.) Transversely ovate; beak prominent; hinge-lino arcuated; with prominent ribs from 
umbones to base; sides deeply reflexo-dextate. 
58, 59. T. Anisodonta. (Unequal-notched Terebratula.) Transversely oval, depressed ; beak prominent; front straight, with large, angular 
elevation ; mesial edge straight, indented by six, narrow ribs ; sides reflected towards deeper valve ; broadly and deeply notched. 
GO, 01. T. Chrysalis. (Chrysalid Terebratula.) Oblong-ovate, sub-compressed; beak long, acute, incurved; hinge-line of smaller valve 
straight, with auriform processes ; with largish ribs ; margin crenulated. 
a a I* * FlexistPia. (iratvd Striate Terebratula.) Oblate, sub-depressed ; beak minuto ; mesial elevation rounded; lower valve smaller 
ana flatter than the other; sides curved ; with many, flexuous strite. 
bo, 67. T. Gibbsiana. (Gibb's Terebratula.) Sub-orbicular, triangular, inflated; beak small, acute, incurved; with many, simple plaits; 
front elevated, with ten or twelve, flattened plaits. 
69. T. Plicatella. ( Folded Terebratula.) Elongated, quadrangular, inflated; beak small, incurved; with about forty rounded plaits 
sometimes furcated near beaks. ’ 1 ' 
T. Dilatata. (Enlarging Terebratula.) Transversely elliptical, trilobate; central lobe elevated; beak of larger valve short, large; 
with about fifty divergent plaits. * ’ 
Mesogonia. (Interangular Terebratula.) Tetrahedral, frontal elevation single or cleft; sides with one or two ribs. 
<4, T. Cpenulata. (Crenulated Terebratula.) Pentagonal; beaks obtuse, compressed; sides and base parallel; with fine, 
flat intermediate ribs 
deep snlci and 
margins^ ^ Bifera. (Double Terebratula.) Tetrahedral; beak acute; upper valve trilobate; with many, radiating stria?, bifurcating towards 
T * Uallina. (Faicl Terebratula.) Transversely obovate; convex; lower valve, with wide, central sulcus; beak acute, small; both 
valves with wide, longitudinal ribs. ’ 
• An 81 Cpispata. (Curled Terebratula.) Rbomboidal, convex, transverse; beaks small, sub-trilobate ; witli about eighteen, acute plaits; 
sides smooth. Length and breadth, g in. 
T- Acuta. (Acute Terebratula.) Triangular; centre elevated, with one, acutely angular plait; sides, with one large, and several 
smail, lateral pkits - beak obtuse; front, sinus almost an equilateral triangle. 
. i ’ -j ’ i, ei }tllabrum. ( Bellied Terebratula.) Iihomboideo-deltoidal ; margin sharp, with obtuse ribs; upper valve sulcate near obtuse 
b «V B1 H 7 S T b V lue y l. ,arallel - with fiw or six, mesial ribs. 
b,87. T. LatlSSima. (Very Broad Terebratula.) Transversely elongated, convex ; larger valve, with produced beak ; front elevated; with 
forty, narrow, divergent ribs. 
83,89. T. Pectita. (Little Comb Terebratula.) Sub-orbicular, gibbose; with medial hollow from beaks to base; beak produced, incurved; 
’ l^ glltKlmal stn *’ ° fte ” furcated towards the base. 
plaits Obsoleta. (Obsolete Terebratula.) Orbicular, gibbose; centre of front with seven plaits ; beak produced; sides, with seven to eleven 
91. T. Soeialis. (Social Terebratula.) Transversely oblong-ovate ; beak short; mesial elevation with about four ribs; sides rounded; with 
strong, acute ribs. & 
( 67 ) 
