( w ) 



ORDER III. TECTIBRANCHI. 



1. Pleurobranchus. (1) 

 Cuv. 



Body as if between two 

 shields formed by the foot 

 and the mantle ; the lat- 

 ter sometimes containing 

 an oval calcareous plate. 



2. Aplysia. (2) Lin. 



Edges of the foot turn- 

 ed up, flexible, encircling 

 the back in every part : 

 head borne on a neck. 

 PI. 14, fig. 2, 11,* 14. 



3. DolAbella. Lam. 



Body resembling a trun- 

 cated cone • shell calca- 

 reous. 



4. NotArchus. Cuv. 



Mantle with an oblique 

 cleft above the neck com- 

 municating with the bran- 

 chiae. 



GENERA. 



2 Tubulous and cleft Branchial along the 



tentacula on the mouth left side, in the furrow 



(a small trunk), sur- between the mouth and 



mounted by a lip. the foot. 



2 Superior tentacula, Branchiae on the back 

 hollowed like the ears and attached to a stem 

 of a quadruped, with covered by a small mem- 

 the eyes at the base ; 2 branous mantle, con- 

 others flattened and at taining a hollow flat 

 the edge of the lower lip . shell . 



Ditto. 



Ditto. 



Branchiae at the pos- 

 terior extremity of the 

 body. 



Branchiae as in Apla- 

 sia. 



(1) They have four stomachs; the second is fleshy, sometimes armed with bony 

 pieces, and the third furnished interiorly with longitudinal projecting plates ; the 

 intestine is short. 



(2) An enormous membranous crop conducts to a muscular gizzard, armed with- 

 in by pyramidal, cartilaginous corpuscles, followed by a third stomach sown with 

 sharp crooks, and a fourth in the form of a coecum : the intestine is voluminous. 

 These animals feed on fucus. A peculiar gland furnishes, by an orifice situated 

 near the womb, a limpid humour, which is said to be sour in some species ; a deep 

 purple liquor issues abundantly from the edges of the mantle, with which the 

 animal colors the water to a considerable distance on the approach of danger. 

 When Apuleius was accused of magic and poisoning, it was reported as a principal 

 evidence that he had engaged some fishermen to procure him an Aplysia (Sea- 

 Hare) ; and it is to the following part of his description that we owe the only cha- 

 racteristic which has enabled us to recognise so celebrated an animal. " It has 

 an extraordinary property, of which my predecessors have been ignorant, which 

 is, that being otherwise destitute of bone, it has twelve small ones in its belly, 

 similar to the astragali of the hog, attached and tied together." The form of the 

 Aplysia explains the name of Sea- liar c ; and their smell, and the liquor which they 

 produce, account for the pernicious properties attributed to them. 



