88 Moll. 
MOLLUSCA. 
tive of the edible and other species, as those referring to anatomy, 
physiology, and artificial breeding, with short abstracts of the contents 
of the more important ; Tijdschr. Ned. Dierk. Yer. Suppl. i. pp. 1-112. 
Description of the renal organ of the oyster by J. A. Ryder, and of 
the genital organs by P. P. C. Hoek ; vide supra , Anatomy and Physi- 
ology, pp. 15 & 17. 
J. A. Ryder has observed in Ostrea virginea that the very young shell, 
just hatched and still free, is equivalvular and equally convex on both 
sides, and has a laminar, homogeneous, non-prismatic structure ; it then 
fixes itself at the free border of the lower valve by a pallial secretion 
(probably conchioline) of the periostracum, the embryonal part of the 
shell remaining inclined upwards ; and from that time the newly -formed 
parts of the shell are of prismatic structure, and those of the lower valve 
are attached to the foreign body for some time. Bull. U. S. Fish. Comm, 
ii. pp. 383-386, pi. 
J. A. Ryder gives an account of a successful experiment of rearing 
artificially-fertilized eggs of oysters in ponds at Stockton, Maryland, as 
practised for many years in France, and adds some interesting particulars 
of the habits and growth of the oyster. The food of very young oysters 
is largely composed of Bacteria ; in the stomach of the adult, are often 
found very young oysters, from g-^o-^o °f an inch in diameter, Diato - 
macece , very young Cirripeds, and marine Infusoria , e.g., Tintinnus. The 
young Virginian oyster attaches itself very soon, twenty-four to forty- 
eight hours after the eggs have been fertilized, and grows considerably 
after the time of attachment before the valves lose the perfect symmetry 
of the larval stage. Green-gilled oysters are by no means noxious to 
man, the colour arising from vegetable and not mineral matter. Bull. 
U. S. Fish. Comm. iii. pp. 281-294 ; also Science, 1883, pp. 60-62. 
The Infusorian Trypanosoma and Hexamitus found in the stomach and 
intestines of Ostrea edulis and 0. angulata in France by A. Certes, C.R. 
xciv. [1882] p. 463, and Bull. Soc. Zool. vi. [1882] p. 346, pi. vii. ; the 
former also in the crystalline style of oysters from Schleswig by 
K. Mobius, Zool. Anz. 1883, p. 148. 
On some instances of pearls found in oysters, and differences between 
Qstrea edulis (L.) and 0. hippopus (Lam.) ; E. Friedel, Nachr. mal. Ges. 
1883, pp. 46-48. 
A new disease in oysters at Rappahannok : Kobelt, Nachr. mal. Ges. 
1883, p. 116. 
MObius’s treatise on the oyster [Zool. Rec. xiv. Moll. p. 86] is 
translated in U. S. Fish. Comm. Rep. for 1880, published in 1883, 
pp. 683-751, with index and electrotypes of the figures. Also some other 
papers on French oyster culture by F. Fraiche (n. d.), Coste, 1861, with 
many tables, De Bon, 1875, G. Bouchon-Brandely, 1878, J. Renaud, 
1878, and A. E. Hausser, 1876 ; on Dutch oyster culture, by an anonymous 
author, 1881, and P. P. C. Hoek, 1879; and on the Norwegian, by H. H. 
Rasch : pp. 753-1043. 
P. Brocchi & G. Musset have written a treatise on the breeding of 
oysters [title, supra]. H. Griesbach treats the same subject, with special 
regard to oysters in Schleswig-Holstein ; Kosmos, xiii. pp. 449-463, 2 pis. 
