E. Mantle-Border scaly.
C. Coquimitensis, Frembley. Shell ovate, narrow, opaque, green ish-brown, shining ; inside blackish : the anterior valves with numerous undulated, con centric ridges ; the next rather acutely keeled ; the five following alike : carina broad and smooth, on each side of which is a similar ridge diverging from the beaks, and forming with the earina a sagittate figure, and connected with it by several strongly marked ridges : from under the beaks to the anterior angles of the valves extend sharp moniliforrn ridges, each side of which is coarsely striated longitudinally. Border thick, moderately broad, and covered with coarse seed-like scales, which are attached laterally. Length 3 inches, breadth 1,1 inch. Mr. Frembley says, that the only part of the Nast where he found this species was the south side of Coquimbo Bay : their habits, ho adds, are very similar to those of a spini ferns, with the exception that they seem more gregarious.
C. Mantle-Border grauulous.
C. magnificus, Deshayes (C. olivaceus, Frembley ; C. lat us, Sowerby). Shell opaque, ovate, olivaccous, dull, dotted with lighter coloured spots : inside glaucous. Anterior valve with regular radiating striae, crossed by concentric ridges ; posterior margin nearly straight. Dorsal valves obtusely beaked, divided laterally into two compartments, the y anterior having regular longitudinal stria•, crossed with others very minute and concentric ; from under tho beaks diverge to the lateral margins of the valves coarse and more irregular stria, which raise the posterior compartment above the other. The posterior valve has a well-defined apex, leaning towards the posterior margin. Border thin, moderately broad, and covered with fine shining bead-like granu lations, of the same colour as the shells, divided into two distinct portions, the upper of which is composed of finer beads than the lower, and which are placed transversely. (Fremblcy.) The species grows to the length of 4 or 5 inches: we have seen one that reached 4i inches when dead. There is another variety narrower than the
ordinary individuals, and Mr. Frembley observes that, among the very young shells, some of them have their borders of a lighter colour than their shells, and spotted with black. Locality, Chili.
Exogenous Plants, by Koine Wecounted allies of Malraterr, but more correctly referred to the vicinity of Cistame, from which, and all those associnted with them in the Gynotsvde Group, they differ in having an involuerum to each calyx, or to each pair of calicea. They are handsome trees or shrubs, but of no known use. Their leaves are alternate and undivided, their stipules deciduous, and their flowers in panicles or racemes, always showy, and often red. There are four genera, Sarcolama, hplotals, Schizoluma, Ilkodokrna. The whole of the species, about eight in number, are wild in Madagascar.
Species with the Mantle-Border highly developed, and the valves very small. (Chitonellua).
These are more or less cylindrical, and vermiform, the valves being very small, and in some species almost entirely hidden under the skin of the border, giving the animal an almost naked appearance.
Examples, Chitonellus lwris, and C. larraformis.
The following species are noted as British in Messrs. Forbea and Hanley's 'History of fmcicularia, C. discrepam, C. flankyi, C. raber, C. einem', C. albus, C. ascllue, C. cancellatuR, C. hrria, C. marmoreus, and a punetarus.
Above 200 species of this family Lave been described. The genus Chiron is divided by Dr. J. E. G rayand others into numerous sub-genera. Font? Chilonidfr.
Although from their fragility it might be supposed that few remains of these animals would be found, indications of their existence have been discovered as far back as the Paleozoic ponied. About 24 fossil species have been discovered. Three of these are given in Mr. Searles Wood's account of the Crag 31ollusca, published by the Palmontogrophical Society.