vessel, which is turned towards the interior of the ovary, and at the expense of the epithelial cells forming that wall, to which, at first, they remain attached by a peduncle; they afterwards become detached, descend along the lobe, and then arrive in the oviducts; thus they never fall into the general cavity. The sexual lobes are of very unequal length in the same animal, and unequally developed in different individuals according to the age; in Sternaspides of large size, especially in the males, they present short secondary lobes along the principal branches of the sexual vessel. In front of the oviducts and involved in the folds of the œsophagus, there exist two voluminous segmental organs ("fourhorned organs" of Müller), of a brown colour, with delicate walls, irregularly lobed, and each furnished with an excretory canal, which becomes much narrowed towards the integuments, and opens outwards by an extremely small pore. The two symmetrical pores are placed in front of the genital appendages. I have not yet succeeded in detecting vibratile funnels in connexion with these organs; they present an internal epithelium and an external peritoneal layer, and between the two a rich network of often capillary bloodsinuses. Hitherto I have only been able to observe the first phases of the embryogeny as the result of artificial fecundations. The ova are about 0.15 millim. in diameter; within their chorion, which usually retains a trace of the pedicle, they present a granular vitelline mass with an eccentric nucleus and a nucleolus; this nucleus disappears in the mature ova. The spermatozoids are from 0.085 to 0.10 millim. in length; the head is elongated, and occupies about one sixth of the entire length. The segmentation is complete; it commences about five hours after fecundation. Even the first two spheres are unequal; and the difference becomes rapidly more accentuated between the small hyaline evolutive cells and the large, dark, granular nutritive cells; the former quickly envelop the latter, and thus form planula by epibolism. In four-and-twenty hours I found in the glasses pelagic larvæ composed of an ectoderm with small elements, and an endoderm formed of a few large brownish spheres; they appear to be destitute of both mouth and anus. These larvæ are covered with vibratile cilia, except in the posterior region; at their cephalic pole they bear a plume of longer cilia. But the pelagic life hardly lasts longer than from thirty-six to forty hours; the larvæ fall to the bottom of the water, lose their cilia, become elongated, and assume a vermiform appearance and movements. The evolution is afterwards very slow in the glasses; at the end of a month the larvae, although considerably more elongated, present a digestive tube formed of large cells and destitute of mouth and anus; its cavity is filled with a liquid which bears numerous granules, and which the movements of the body cause to travel from before backward or vice versa; in the posterior region and on the dorsal (?) surface we may distinguish a small ectodermal appendage bent into a hook, which may be the first rudiment of the branchia.-Comptes Rendus, May 2, 1881, p. 1066. 308; on specimens dredged up Chalcotania, new species of, 462. Cholus, new species of, 44. Coleoptera, new, 38, 298, 299, 408, Coniocylis, characters of the new Conotrachelus, new species of, 303. known species of Devonian, 14. Crustacea from Franz-Josef Land, on the, 45; of the Caribbean Sea 299. Cydianirus, new species of, 300. Dacnirus, characters of the new Daimio, new species of, 140. Davis, J. W., on Palæospinax pris- Deilephila, new species of, 317. a pathogenic Detmers, Prof., on Dredging, results of, off the south Duncan, Prof. P. M., on the coralli- Dysidea Kirkii, observations on, 374. Edesius, characters of the new genus, Eels, on the male, compared with Elwes, H. J., on Japanese Butter- Emmeria, characters of the new Endophyllum, new species of, 14. Estigmena, new species of, 461. Euperissus, characters of the new Euphoberia, on the structure and Eupithecia, new species of, 320. Exorides, characters of the new Favosites punctatus, description and Fenestellidæ, on the Carboniferous, Filhol, H., on the bears of the ca- vern of Lherm, 428. Flints, on the origin and formation Fol, Prof. H., on the Tintinnodea, Foraminifera, new, from the Gulf of Fungi, notices of British, 123. Gasteropoda, on some fossil opercula Gaudry, A., on a highly organized Gloeosporium, new species of, 129. 129. Hincks, Rev. T., on marine Polyzoa, Joliet, L., on the anatomy of Pyro- Jourdan, E., on the organs of taste Kolga, description of the new genus, Koren, J., on some Arctic Holothu- Kunker formation of the alluvium Laopteryx, description of the new Lataste, F., on a new genus of Ro- Latrunculia, new species of, 380. 333, 392; of the Isle of Askold, Loligo Pealei, on the regeneration of Lütken, Dr. C. F., on the changes of form in fishes during their growth Miers, E. J., on Crustacea and Pre- Milleria, new species of, 35. |