SECTION B.-GENERA WITH APERTURES AT BOTH ENDS OF THE TEST.

Shepheardella, SIDDALL.

Test hyaline, elongate, tubular, cylindrical or flattened, ends slightly tapering towards the apertures. Nucleus large and complex.

EXAMPLE.-S. tæniformis, Siddall, 'Quart. Journ. Micr. Sci.,' N.S., vol. xx. 1880, p. 131, pl. xv. Habitat, marine, in shore pools, on marine algæ. (Plate 1, fig. E.)

Amphitrema, ARCHER.

Test more or less covered by foreign arenaceous particles; apertures at opposite ends of the test and provided with a rimlike neck, giving off two tufts of elongate, linear, branched, pellucid pseudopodia.

EXAMPLE.-A. Wrightianum, Archer, Quart. Journ. Micr. Sci.,' N.S., vol. x. 1870, p. 122, pl. xx. figs. 4, 5. Habitat, fresh water, in boggy places, Ireland. Length of test about 05 mm. fig. F.)

(Plate 1,

Genera sometimes referred to the GROMIIDE: Protogenes (by Claus); Lagynis (by Carpenter).

EXPLANATION OF PLATE 1.

FIG.

A. Lieberkuchnia Wageneri, Clap. and Lachm. Magnified

B. Mikrogromia socialis, Archer sp. * 200.

C. Gromia oviformis, Dujardin. × 25.

D. Diaphoropodon mobile, Archer. x 100.

E. Shepheardella tæniformis, Siddall. Magnified.

F. Amphitrema Wrightianum, Archer.

× 300.

75

CHAPTER VIII

THE FAMILY MILIOLIDE

THIS very important division comprises the whole of the porcellanous-shelled Foraminifera, and the tests. are further distinguished by their imperforate shellwall (sub-order Imperforata vel Porcellanea, Rupert Jones).

They are divided by H. B. Brady into six subfamilies, more or less closely related to one another.

The characteristic features of the foraminiferal shell in the family MILIOLIDE are as follows :—

Test imperforate; normally calcareous and porcellaneous, sometimes encrusted with sand; under starved conditions (e.g. in brackish water) becoming chitinous or chitino-arenaceous; at abyssal depths occasionally consisting of a thin, homogeneous, imperforate, siliceous film' (H. B. Brady).

The shell wall of the miliolids is in nearly all cases of a smooth texture and usually chalk-white in appearance. In some examples, however, the surface is pitted, reticulated, or furrowed, whilst others have their surfaces encrusted with sand grains or shelly particles. Young specimens are, as a rule, translucent and opalescent. This latter appearance is a marked character with the group, for on mounting a