5. Millepora cylindrica, Say.—Branched, cylindric; pores very regular, alternate, oval, placed nearer to each other than the length of their own transverse diameters, and resembling those of an alveolite.
Diameter, about one-tenth of an inch.
6. Segments of the column of encrinus of authors, of a pentangular form.
7. Ossiculæ of the body of a crinoid animal of the analogous species to No. 21.
8. Fragment of Perna?
9. A mass of argillaceous sandstone, containing spines of a Linnæan echinus, belonging probably to the genus cidarites of Lamarck. Of these spines some are elongate-conic, others slightly fusiform, obtuse and slightly dilated near the tip, both are armed with short asperities throughout their length. They resemble in some degree those of the cidarites pistillaris of Lamarck, but they are smaller, less fusiform, and the asperities are not prominent.
In the same mass are segments of encrinus, and fragments of the retepore.
10. Retepore, much resembling the milleporites flustriformis of Martin, Petrif. Derbi. pl. 43. fig. 1 and 2., but the alveoles in our specimens are rather smaller.
11. Millepora cylindrica, Say.—Of the diameter of half an inch.
12. Productus subserratus, Say.—Shell transverse, convex valve semicircular, destitute of asperities or striæ, longitudinally indented in the middle; line of the hinge rectilinear, half as long again as the length of the shell, with three or four spines or serratures on each side towards the angle; umbo not prominent; the beak hardly prominent beyond the line of the hinge. Length, more than three-tenths; breadth, more than half an inch. A large specimen was four-fifths of an inch wide.