MOLLUSCA. 1 79 



ancients {Fig. 167). The first which our dredge bronj,'ht up 

 was placed on one of the rowing benches of the boat, and 

 emitted a rich purplish fluid so copiously that it ran along the 





Fig. 167.— Aplysia. 



board. Being transferred to a phial of sea-water, the purple 

 dye was still given off in such abundance that the creature 

 soon became indiscernible. It was not until the water was 

 changed that we had the opportunity of obsen-ing the ease 

 and grace with which it moved about, elevating and depress- 

 ing its mantle, altering the outline of its body, and extending 

 and retracting its tentacula so incessantly, that an artist 

 would have found a difficulty in catching its characteristic 

 figure. It is probable that the form of the upper pair of 

 tentacula suggested the idea of the ears of the hare, and thus 

 gave origin to its common title. The body of this species 

 {A. depilans) was marked with numerous brownish spots, of 

 irregular size and form ; but when the animal died and the 

 body was placed in spirits, the beautiful s}X)tted epidermis 

 disappeared off the larger portion. This creature, it was 

 once believed, held such antipathy to man that its touch 

 would cause the hair to fall off; and it also was said to 

 supply a poison, the operation of which was speedy and 

 inevitable. Time has stripped this inoffensive creature of 

 these imaginary powers. 



Of the tribes which breathe by lungs (Pulmonata) the 

 common Slugs and Snails offer familiar examples. Even of 

 these species, which are aquatic, many come to the surface 

 for respiration, and float or move with the back downwards. 

 *' On a Summer's day," says Dr. Johnston,* " any one may 



• JIag. Nat Hist vol. iii. patjo 531. 



