The chalk and flints of Sussex abound in these crosier-like shells, whose existence in the cretaceous rocks was first made known by my deeply lamented friend, the late Marquis of Northampton. The annexed lignograph, from drawings by his lordship, shows the form and structure as displayed by sections in fractured flints. Four species were named by Lord Northampton (see Wond. p. 32-5); but it is doubtful whether all the specimens belong to more than one species; the apparent diversity of structure may arise simply from the different planes in which the sections happen to have been made.
Globigerina. [Lign. 109, fig. 1.]—The shell is turbinated, the cells are spheroidal, and the last, or terminal one, has a semilunar aperture at the umbilical angle. Several fossil species abound in the Chalk and in the tertiary deposits; and many living species swarm in our seas.
Lign. 113. Nonionina Germanica, × 290.
A recent specimen of the body of the animal; the shell removed by acids.
From the North Sea, Cuxhaven. (M. Ehrenberg.)
a, a.—Naviculæ and other organisms in the segments of the animal.
Nonionina.—[Lign. 113.]—A nautiloid shell, with simple cells; the last cell has a single narrow aperture placed transversely over the dorsal aspect of the spire. One species occurs in the chalk formation of Germany; several in tertiary deposits, and in the existing seas.
The figure, [Lign. 113], represents the body of the animal deprived of its shell, to illustrate the nature of certain fossils from the Chalk.
Lign. 114. Foraminifera in Chalk and Flint. × ×.
(Seen by transmitted light.)