1— A magnificent Polycystin, from Cambridge, Barbados. It measures .0214 in height, viz., the ball .0028, and .0186 from the ball to the base, where several more
squares appear to have been broken off, — about 18 to 20 rows of squares, like windows; inside soine of them a very fine internal network is seen; through others appear a faint reflection of the bars on the opposite side of the object : the effect of this, viewed in the Binocular (half-inch objective), is very striking.
2— Eucyrtidium Tubulous, Ehr., measures .01 feet long, .0028 broad, from Peak of Teneriffe, Barbados. Quarter- inch objective.
3- Stylosphsera (?) Ehr., measures .01 high, curiously beset with sharp, spear-like spines, and covered apparently with pointed knobs or warts. Some of the Barbados Polyeystins suggest an idea as if their perforations either may have been, or might have become occupied by these sort of projections, which, when broken off, leave holes, and being hollow, would still permit the protrusion of the so-called Pseudopodian
threads, which Professor J. Miiller says " one may conjecture (Termuthcn) " to be the means by which the Polyeystins imbibe nourishment, although their connexion with the Sarcode substance of the bodies, requires more clear elucidation. In the Thallassicollen and Polycystena, they can only be traced as far as the skin-like Capsule of the flabby part lying under the flint corselet.
4— Dictyospiris (?) probably the same object as fig. 2, on plate II ; turned on the reverse side. Ehrenberg calls this " Ruckseite," and the other with the larger openings, " Mouthside ; " from Cambridge, Barbados.
5— Spongolithis Acicularis, Mik. Taf., XXXVI, fig. 47, a Phvtolitharien of Ehrenberg.
6— Amphidiscus Verticillatus, Mik. Taf., XXXVI, fig. 45, classed by Ehrenberg as " Phytolitharia,"— of plant growth.
