238 DENTALIAD^E. 



it cannot be well seen from the dorsal area, but in transparent 

 individuals may often be observed in the pericardium from the 

 ventral surface, without dissection, between the bases of the 

 stomach and branchiae. 



The following remarks give a more correct view of the 

 character of the liver. The real liver not my branchiae, 

 which M. Deshayes states to be the liver consists of two 

 symmetrical subcentral masses, one on each side, formed of 

 10-15 subrotund, pale to dark brown granular lobes, and 

 of each group the biliary duct can be observed to pierce 

 the peritoneum. With regard to the salivary glands 

 M. Deshayes' branchiae I have again examined them, and 

 traced their pedicles and ducts to spring on each side of 

 the oesophagus at its junction with the stomach, and, as I 

 think, supply the buccal pouch with a lubricating secretion 

 to assist deglutition. I can discover no connection between 

 the heart and these organs. All examples show that the 

 foraminiferous faecal spoil is discharged anteriorly, and I 

 think that there can be no question of the entry of the bran- 

 chial water by the posterior canal, which, with M. Deshayes, 

 is the anal conduit. As a positive proof of this arrangement, 

 I repeat, in confirmation of my former statement, that in 

 many young delicate pellucid individuals, I have both by sun 

 and artificial light seen the water, in whatever position the 

 shell is held, ascend and descend in the tube for the aeration 

 of the blood, by alternate contraction and dilatation ; in fresh 

 animals the inspirations and expirations are, each, 5-8 in a 

 minute, or together 10-16 ; but when they have been kept 

 some days and suffered from want of food, the times of the 

 two actions are more irregular and fewer ; and still more so 

 when the water has become effete, by the animal being long 

 detained under examination : these processes can be observed 

 for many days until nature is exhausted. I submit that these 

 are strong reasons in support of the posterior admission of the 

 branchial water, and that what has been called the anal issue 

 is undoubtedly the aquiferous canal. I again beg to impress 

 on zoologists, that no organ of simple depuration or excretion 

 is ever under systole and diastole influences. 



