Ammonita. MOLLUSCA. CEPHALOPODA. ^45 
keel broad, obscure, crenulated within. — Sower. Min. Conch, t. xcii. f. S.—In 
clay, Middle Oolite^ Scarborough. 
58. A. bina — Depressed, keeled, whorls 4, the inner ones two-thirds ex- 
posed ; ribs diverging in pairs from round tubercles, swelling and then turn- 
ing up towards the front, and disappearing ; aperture oblong rectangular, the 
angles rounded. — Sower. Min. Conch, t. xcii. f. 3. — Plastic Clay^ Bramerton 
Norfolk. 
59. A. armata — Whorls 6, exposed, with many annular undulations, arm- 
ed with two rows of large conical short furrowed spines ; aperture obscurely 
four sided — Sower. Min. Conch, t. xcv.— -In Lias^ Whitby. 
60. A. monilis — Whorls 4, exposed, subumbilicate, the outer margin rather 
depressed ; ribs tuberculated, striated ; aperture transversely ovate.^ — Sower. 
Min. Conch, t. cxvii. — Green <S'awd, Folkstone. 
61. A. Depressed, whorls 5, exposed, with obscure radiating un- 
dulations, tuberculated at their origin ; back deeply channelled, bordered by 
large alternating compressed tubercles — Sower. Min. Conch, t. cxxxiv — In 
Green Sand. 
62. A. Duncani. — Depressed, inner whorls partly exposed ; edge fiat, bound- 
ed by two rows of tubercles ; ribs numerous, undulated, irregularly furcate ; 
aperture ovato-sagittate.-— Min. Conch, t. clvii — In the clay of the 
Middle Oolite. 
63. A. vertehralis — ^Whorls 4, inner ones parti}?- concealed, carinated ; ribs 
numerous, prominent, tuberculate in the middle, then furcate, with a tuber- 
cle on each branch ; keel serrato-tuberculate ; aperture orbiculate. — Soioer. 
Min. Conch, t. clxv. — In Middle Oolite., near Abingdon, Berkshire. 
64. A. //ewfeyi— .Whorls few, increasing rapidly, the inner ones exposed ; 
ribs numerous, with two compressed tubercles upon each ; the ribs usually 
divided from the outer tubercle ; aperture large, slightly round. — Sower. Min. 
Conch, t. clxxiii. — In Lias^ Dorsetshire. 
65. A. rostrata — Shell depressed, carinated ; whorls 4, exposed; ribs large, 
obtuse, with three or four tubercles, largest in front ; aperture elliptical, with 
a compressed reflected beak.. — Sower. Min. Conch, t. clxxiii.— -In Chalk Marl., 
Oxfordshire. 
66. A. 'aanaws.— Depressed, carinated, whorls 3, half exposed ; a row of 
large tubercles near the front, and one or two rows of lesser tubercles placed 
upon furcate radiating undulations..^ — Sower. Min. Conch, t. clxxvi.— >In Chalk 
Marl. 
67- A. injlata -Depressed, inner whorls exposed, carinated, sides and front 
flattish ; ribs commencing with a compressed tubercle, then furcate ; keel 
distinct ; aperture square.~iS'ow<sr. Min. Conch, t. clxxviii — In Green Sand., 
Isle of Wight. 
68. A. Depressed ; whorls 3 ; gibbose, exposed, with 6 or 8 conical 
tubercles upon the sides of each, and two rows of obtuse tubercles around the 
front, which is flat ; aperture quadrangular.—iS'owen Min. Conch, t. clxxvii. 
.. — In the Lower Chalk., near Lyme. 
69. A. Banksii Whorls 5, exposed, sides concave, largely tuberculated ; 
front fluted, slightly convex; aperture transverse, almost three times as long 
as wide — Sower. Min. Conch, t. cc. — Under Oolite. 
70. A. Blagdeni. — Subcylindrical, obtusely fluted, umbilicate; umbilicus 
reaching to the margin, conical, with large radii, terminating upon the edge 
