f 
ANODONTA, 273 
supra-branchial chambers from the mantle-cavity below. 
Posteriorly these lead into the exhalent chamber. ‘The water 
appears to pass between the gill-filaments directly into the 
supra-branchial and exhalent chambers, erating the blood 
in the gill-filaments in its course. The food-particles appear 
to pass forward to the mouth, which is situated just under 
the anterior adductor muscle. They are assisted by a pair 
of flat triangular /adca/ palps in each side. From this it is 
seen that the ctenidia serve the two purposes of alimentation 
Fig. 192.—DIssECTION OF ANODONTA FROM LEFT SIDE 
(Slightly Diagrammatic). 
Aperture of Kidney into Pericardium. 
Digestive Gland. Dorsal 
Aperture of Digestive | Artery. 
Gland into Stomach. 
Ventricle of | 
Heart. Pericardium, 
*ra}21Q) 
Intestine, 
Anterior 
Adductor. Dorsal 
Canal 
38 
mol 
i=} 
< 
Mouth. 3 
ao 
Cerebral ied 5 
anglion, Ay 
ao 
a 
Poste.ior 
Adductor. 
Visceral Ganglion. 
Pedal Ganglion. Intestine. Kidney. 
Gonad. 
(food ingestion) and of respiration. They appear to be 
derived from organs of the same nature as the gills of other 
molluscs. ee 
The mouth leads into a short esophagus passing into a 
globular stomach, into which open the ducts of a digestive 
gland. From the stomach the long zu/estine de- 
scends into the base of the foot, and after com- 
plex coils it again ascends to the dorsal region and passes 
backwards over the posterior adductor muscle to open by an 
anus into the exhalent aperture. We may note the entire 
absence of “head,” buccal mass and odontophore. 
M 19 
Alimentary. 
