MOLLUSC A. 169 



which communicates with it, and again contracts and unites 

 with its fellow from the opposite side, to form the auricle. 

 A single aorta arises from the anterior side. The ovarium 

 is conical, and divided into numerous lobes. Behind, two 

 ducts seem to arise, and to proceed one to each side ; but 

 it has not been determined whether they open externally. 

 No male organs have been detected ; nor is there any thing 

 accurately known with regard to the peculiar nature of their 

 hermaphroditism. 



GENUS PHYLLIDIA. Anus placed dorsally near tiie ex- 

 tremity of the cloak. The body, in the animals of this 

 genus, is ovate. The foot is narrow in front. The cloak 

 is broad, coriaceous, and destitute of a shell. Towards its 

 anterior extremity are two cavities, from which issue the 

 retractile superior tentacula, as in the genus Doris. Nearly 

 at the posterior extremity is another cavity, containing the 

 anus. This opening, though similar in situation to that of 

 the Doris, is merely a short simple tube. The head is im- 

 mediately above the anterior margin of the foot, above which 

 is the mouth, having a small conical feeler on each side. 

 Under the margin of the cloak on the right side, and about 

 half way between the mouth and the middle of the body, 

 are two openings, in a tubercle, for the organs of genera- 

 tion. The branchiae consist of slender complicated leaves, 

 which surround the body between the foot and the cloak. 

 The circle is interrupted at the head and at the tubercle 'if 

 generation. The mouth is destitute of jaws. The gullet is 

 simple, ending in a membranaceous stomach. The pylorus 

 is placed near the cardia, and the intestine goes directly to 

 the anus. The salivary glands are small, and placed near 

 the mouth. The liver is large in proportion. The heart is 

 situate in the middle of the back. The auricle is simple, 



