Mr. F. Walker on some British Chalcidites. 181 there is no fresh nutriment for organized beings of any kind, has become untenable. 10. Life and temperature in the depths of the ocean are, in their variable relation, the points which at present deserve espe-cial attention. 11. The showers of meteoric dust, or supposed ashes, have at present been proved to be, even in the case where they fell 380 sea-miles from land, of organic and terrestrial origin. 12. It is not perishable Protococci or Ulvce or Lichens that principally constitutes the organic covering and soil of the ulti-mate islands in the Polar Sea ; but the living creatures that form the first layer of solid earth are invisible, minute, free animals of the genera Pinnularia, Eunotia and Stauroneis with their siliceous loricse. Several species from the North Pole and the South Pole are identical. XXIII. — Descriptions of some British Chalcidites. By Francis Walker, Esq., F.L.S. Callimome Rasaces, Fem. Cupreus purpureo varius, metathorace viridi, abdomine cyaneo bast rufo, antennis nigris, pedibus fulvis, alis subfuscis. (Corp. long. lin. 2 ; alar. lin. 3.) Body convex : head and thorax cupreous, tinged with purple, covered with minute scales disposed in little transverse striae : head short, transverse, a little broader than the thorax : antennae subcla-vate, black, as long as the thorax ; first joint fulvous, long, stout, linear, black towards the tip ; second cyathiform ; third and fourth very minute ; fifth and following joints to the club successively de-creasing in length ; club long-conical, acuminate, much more than twice the length of the eleventh joint : thorax elliptical, punctured sparingly and irregularly : prothorax large, subquadrate ; its breadth exceeding its length ; rounded on each side in front : scutum of the mesothorax large, its breadth slightly exceeding its length ; sutures of the parapsides distinct, approaching each other; axillae large, triangular, not conniving ; scutellum nearly rhomboidal, of moderate size, abruptly decumbent behind : metathorax including the propo-deon short, transverse, rugulose, mostly green : podeon extremely short : abdomen elliptical, subcompressed, smooth, dark blue varied with purple, as long as the thorax ; metapodeon pale red, occupying rather more than one-fourth of the dorsum ; octoon much snorter than the metapodeon; ennaton much longer? than the octoon; decaton as long? as the octoon; protelum, paratelum and telum short : oviduct a little longer than the abdomen : legs stout, fulvous : wings slightly fuscous; nervures piceous; humerus less than half the length of the wing; ulna more than half the length of the humerus ; radius about one-fourth of the length of the ulna ; cubitus extremely short, not so long as the radius ; stigma of moderate size, emitting a short stout branch that points towards the tip of the radius.