Scientific Serials

Abstract

The Quarterly Journal of Microscopical Science for April, 1893, contains:—Description of a new species of Moniligaster from India, by W. Blaxland Benham (PI. xxxii. and iii.). The species is from the Nilgiris and is named M. indicus.—Note on a new species of the genus Nais, by W. Blaxland Benham (PI. xxxiii.). The worm was found in a ditch in the neighbourhood of Oxford; it is of a dull brownish colour, about a quarter of an inch in length, and is called N. heterochæta, from the fact that of the normally two chætæ in the dorsal bundles one is of a “crochet” shape, the other is capilliform.—On a new organ in the Lycoridea, and on the nephridium in Nereis diversicolor, O. F. Muell., by E. S. Goodrich (PI. xxxiv. and xxxv.). The new organ consists of a pair of large, highly-differentiated, ciliated patches of cœlomic epithelium, which are found in every segment, except the first and the last few. These “dorsal ciliated organs” seem to occur throughout the Lycoridea, having been found in all the genera of that family examined by the author. Some notes on the minute structure of the nephridia of the Nereids are added.—On the nephridia and body-cavity of some Decapod Crustacea, by Edgar J. Allen, (PI. xxxvi. vii. viii.). 1. The green gland of Palæmonetes (and Palæmon) at the time of the hatching of the larva has not developed a lumen. When the larva leaves the egg the lumen commences to open and the gland consists of an end-sac and a U-shaped tube, of which the distal portion gives rise to the bladder. The bladder then enlarges greatly, growing at first inwards towards the middle ventral line, then upwards, within the œsophageal nerve-ring and anterior to the œsophagus, to the middle dorsal line, where it meets its fellow of the opposite side. The two bladders grow backwards over the stomach and beneath the dorsal sac, subsequently fusing together in the middle line to form the unpaired nephro-peritoneal sac. 2. The shell-glands are the functional excretory organs at the time of the hatching and during the latter part of the embryonal period. They open at the bases of the second maxillæ, and each consists of an end-sac and a Y-shaped renal tube, which have the typical structure of a crustacean nephridium. 3. A dorsal sac, which is completely enclosed by an epithelial lining, persists in adults of Palæmon, Palæmonetes, and Crangon. 4. At its anterior end the dorsal sac is surrounded by a mass of tissue which appears to have the power of producing blood corpuscles. 5. The dorsal sac is formed as a hollowing-out in masses of mesoderm cells, which lie on either side of the cephalic aorta. 6. The body-cavity of these Crustaceans varies in different regions: (a) In the anterior part of the thorax it consists of a true cœlom (the dorsal sac and nephridia) and a hæmoccele; (b) in the posterior part of the thorax and in the abdomen, the body cavity is entirely a hæmoccele.—Note on the cœlom and vascular system of the Mollusca and Arthropoda, by Prof. E. Ray Lankester. A reprint of an abstract of an important paper read at the 1887 meeting of the British Association, and published in these pages (vol. xxxvii. p, 498). The author adds a request for specimens of Lernanthropus to enable him to complete his researches. Five species of this genus are recorded from the Mediterranean in Cams' “Prodomus Faunae Mediterranese.”—Contributions to a knowledge of British marine Turbellaria, by F. W. Gamble (PI. xxxix.-xli.), records 71 species, of which 28 are now added to the British fauna. Plate xxxix. contains coloured figures of ten species.—Peculiarities in the segmentation of certain Polychætes, by Florence Buchanan (PI. xlii.).—Review of Bolsius' researches on the nephridia of Lee ches by A. G. Bourne.