MESSRS. HANCOCK AND EMBLETON ON THE ANATOMY OF DORIS. 215 
seen a fine net\YOi'k or delicate arborescence of very minute vessels enveloping the 
organs. The whole alimentary canal, the pancreas and the great hepatic duct are 
likewise enveloped in the irregular meshes of the sympathetic system of nerves. 
Varieties. — In D. tuberculata^YE^ANY , and D .verrucosa, C\]x .,wq have the alimentary 
apparatus formed on the whole after the same type as that in the British D. tuhercu- 
lata, only in D. verrucosa* we have at the commencement of the oesophagus an 
extensive membranous pouch or crop projecting forwards, and the stomach is much 
reduced in size. The salivary glands are folliculated. 
In D. Johnstoni^, we have extending from the buccal mass to the cleft of the liver, 
where it receives the hepatic duct, a simple tube dilated at its upper part ; this dila- 
tation may be looked upon as a sort of crop or anterior stomach. The intestine 
comes off upwardly immediately after the junction of the hepatic ducts, and though 
there is here no well-marked dilatation, we believe from analogy that the anterior 
part of what is here called intestine may perform the part of stomach ; the salivary 
glands are very slender, almost linear, plain tubes. 
In D. pilosaj^, at the commencement of the oesophagus, is an extensive membranous 
pouch ; to this succeeds a much-contracted tube, which suddenly dilates into a fusi- 
form sac like the crop or anterior stomach of D. Johnstoni. A tube from the oppo- 
site end of the sac plunges into the middle of the anterior surface of the liver, which 
is not cleft as in the previous species. The tube becomes dilated within the liver, 
and penetrates to about one-third the length of that organ, after which it curves 
upwards and slightly forwards, and emerges from its upper surface. After this the 
tube, still dilated, runs a little forward, and is then bent upon itself, at the same time 
becoming contracted in calibre, and having appended to it a small pancreas, assumes 
the usual course to the anus. That part of the tube enclosed within the substance 
of the liver receives three or four large hepatic ducts at the posterior and under 
part of the curve, and together with its continuation as far as the pancreas, must be 
regarded as the true stomach. The present species has its salivary glands curved 
and folliculated at the buccal end. 
The alimentary tube of D. hilamellata^ is formed on the same plan as the last 
described ; only the crop or anterior stomach dilfers somewhat in form, and has its 
walls folliculated. The salivary glands are here reduced to a small granulated body 
surrounding the commencement of the oesophagus. 
In D. repanda, D. coccinea, D. aspera, and D. depressa, the alimentary canal ap- 
pears to be cast in the same mould as the last-mentioned species. The inner surface 
of the stomach is plicated in all, and in all the intestine is rather wide, and plicated 
longitudinally throughout. 
The Uver^ is the largest organ in the body, and usually fills up more than the 
posterior half of the visceral cavity. It is of rather a conical form ; the base, which 
is somewhat cleft above, and deeply hollowed out into the shape of a funnel, is 
* Plate XII. fig. 3. t Plate XII. fig. 2. t Plate XII. fig. 4. § Plate XII. fig. 5. |1 Plate XIII. fig. 13. 
MDCCCLU. 2 F 
