318 Miscellaneous, 



On the genus Camptonyx. 



M. P. Fischer, in the * Journal de Conchyhologie' for June 1859, 

 gives the genus Camptonyx, Benson, as a synonym of Valenciennesia, 

 Rousseau, and includes the recent Kattiwar species, C. Theobaldi, 

 as a second form of that genus. 



M. Fischer could not have consulted the original paper in the 

 'Annals' for May 1858 ; otherwise he would have observed that the 

 relations of Camptonyx with the fossil Valenciennia had been pre- 

 viously noticed, and that the different positions of the siphonal 

 channels had been rehed on as sufficient to prevent their union. 



M. Fischer has attributed Campt. Theohaldi to Cochin China, 

 while quoting the true habitat, "sur la peninsule qui separe les 

 Golfes de Kutch et de Cambay.'* The locaUty of this peninsula, 

 between Bombay and the mouths of the Indus, will serve the views 

 of M. Fischer still better than the remote station which he has erro- 

 neously assigned to the recent shell. — W. H. B. 



September 26, 1859. 



Anatomical and Physiological Investigation of the Pleurobranchus 

 aurantiacus. By M. Lacaze-Duthiers. 



Digestion. 



Mouth protractile into a trunk; lingual bulb containing three 

 corneous pieces : one median, comb-like, in consequence of the accu- 

 mulation of an immense number of small sharp lamellar teeth ; and 

 two in the form of laterally symmetrical plates, covered with small 

 points regularly arranged like the teeth of a file. 



CEsophagus long. Stomach simple, large, placed on the left side. 

 Intestine short, without convolutions, scarcely flexuous, opening on 

 the right side behind the branchia. 



Accessory glands. — Liver voluminous, blackish, its excretory ca- 

 nals opening at the union of the stomach and intestine, formed of 

 caeca with cellular contents, often occupied by calcareous calculi or 

 calculi of some other nature, probably biliary, usually of a dark 

 tint. 



Two kinds of salivary glands, one of which, not yet described, as 

 far as I know, is placed upon the dorsal face of the pedal disk, that 

 is to say, upon the lower floor of the visceral cavity, and opens by a 

 single canal between the trunk and the tongue ; it is formed of large 

 caeca, clothed with a cellular tissue of very large cells. The other 

 salivary glands are identical with those of other Mollusca, except 

 that their position is different, their parenchyma being intermixed 

 with the liver. 



Circulation. 



The study of this is most important. The venous circulation is 

 lacunar in the highest degree. The tissue of the animal swells up 

 like a sponge ; great venous tissues, irregular around the stomach, 

 circular at the base of the foot and of the dorsal tegumentary lobe, 

 conduct the blood, on the one hand to the branchia, on the other 

 to the branchial vein, near its union with the auricle. 



