ZOOLOGY. 595 



ing that there is absolutely no fatty matter iu these mollusks, I do most 

 emphatically deny that the winter plumpness of the animal is due to 

 such a cause, but rather to large accumulations of protoplasmic matter 

 of a soft, slimy consistency, identical with the more substantial jjarts 

 of the higher animals. This popular error in regard to the true cause 

 of the plumpness or leanness of the oyster, as the case may be, is only 

 another illustration," adds Mr. Ryder, " of the Very many erroneous ideas 

 of the intensely practical multitude who decry .scientific methods, which 

 are after all only very rigorously exact common sense methods under 

 another name." 



The much-mooted question as to the cause of the green color of some 

 oysters was also inquired into by Mr. Ryder. 



His investigations of green oysters confirmed a former conclusion 

 reached by him — that the color was due to a tinctui e of the blood cells 

 either derived from green vegetable food or possibly by an effect of cer- 

 tain food upon the secretions of liver which have changed in color. The 

 greened blood cells accumulate in some cases iu the interstices of the 

 muscular trabeculoe of the ventricle, and are sometimes even i)acked 

 down behind the auriculo-ventricular valves so as to impede their ac- 

 tion. They apparently lose their amoeboid disposition to a great extent. 

 "This amoebal character of the blood-cell of the oyster is very striking, 

 and may continue to exhibit itself in the living blood-corpuscles ^r 

 four hours after their removal from the animal. The cysts tilled with 

 green cells are simply points in the pallia! vessels which have been dis- 

 tended by these abnormal accumulations. The greenish cells and blood 

 corpuscles are of about the same size, or about l-3,000th of an inch in 

 diameter. They are evidently not parasitic ; none were ever seen to 

 present anything like an appearance of commencing fission." 



GASTROPODS. 



General. 



Dall ("W. H.) On certain Limpets and Chitons from the deep-sea waters off the east- 

 ern coast of the United States. Proc. U. S. Nat. Mus., v. 4, p. 400-414. 



Grabau (H.) Ueberdie Spiralen der Conchylien, mit besonderer Bezngnahme aut d ie 

 Naumann'sche Conchospirale. Leipzig, Hinrich's Veiiag in Comm., 1882 (4to, 39 

 pp. mit 1 Taf. M. 1.) 



Amphineurans. 



Hnbrecht (A. A. \V.) A Contribution to the Morphology of the Amphineura. With 

 woodcuts. Quart. Jour. Miscroscop. Sc, v. 22, p. 212-228. • 



Pitlmonates. 



Morelet (A.) Observations critiques sur le m^moire de M. E. R. Martens, intituld: 

 Mollusques des Mascareignes et des S6chelles. Journ. de Conchyliol., v. 30, pp. 

 85-106. 



Rochebrune (A. T. de). De I'ovoviviparit^ chez les Mollusques pulmonis terrestres 

 inopercul6s. Bull. Soc. Philomath., Paris, t. 6, pp. 219-225. 



