Mr. F. Walker on some new species of Chalcidites. 125 and in a locality not very distant from mine, the earth from Lough Island-Reavey is almost wholly different, including but few spe-cies, and the more numerous of these found but sparingly in the Lough Mourne deposits. The following make up nearly the entire mass of the earth described by Dr. Drummond : — Navicula gracilis. Tabellaria fenestrata. Himantidium arcus. ventricosa. pectinale. A few frustules of the following also occur : — Surirella splendida. Epithemia zebra. Navicula viridis. Cocconema lanceolata. The profusion in which N. gracilis ^ H. pectinale and T. fenes-trata occur in this deposit, would lead to the conclusion that the waters of the lake in which it had been found were the drainage of a subalpine district, whose surface was almost exclusively peat, while the Lough Mourne deposit would, even to the phi-lomicros unacquainted with its locality, indicate the neighbour-hood of clear springs, grassy pastures and a low elevation. In this way these minute organisms may afford matter for interest-ing speculation, and when occurring in a fossil state may possibly be made available in the researches of the geological inquirer. Wareham, January 10, 1850. XV. — Notes on Chalcidites, and Descriptions of various new species. By Francis Walker, F.L.S. [Continued from vol. iii. p. 210.] Caudonia, n. g. Fem. Head and chest convex, very finely shagreened : head thick, a little broader than the chest : feelers slender, subclavate ; first joint long, slender ; second cup-shaped ; third and fourth very small ; the following from the fifth to the tenth successively but slightly de-creasing in length and increasing in breadth ; club long-elliptical, broader than the tenth joint, and more than twice its length : chest spindle-shaped, much developed : fore-chest rather long, having a slight transverse ridge near the hind-border whence it declines and grows narrower and forms a short neck : shield of the mid-chest very long ; sutures of the parapsides distinct for rather more than two-thirds of the length of the chest, but thence quite obsolete ; axillae parted by rather less than one-fifth of the breadth of the chest ; scutcheon nearly conical, with a slight transverse suture towards the hind-border ; hind-scutcheon transverse, but rather large : hind-chest well developed, obconical, declining, with a ridge along the middle and a suture on each side : petiole short : abdomen long-oval, smooth, shining, slightly concave above, rather deeply keeled beneath, some-what broader and a little shorter than the chest ; metapodeon occu-
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