SEA-HARE. 141 



placed upon the middle of the back, and are protected 

 by a broad plate of shell, somewhat like a watch-glass 

 of irregular outline, very thin and transparent, and very 

 brittle when dry. During life, this shelly plate is im- 

 bedded in the substance of the skin of the back, a thin 

 layer of which clothes it ; so thin that it can be very 

 readily seen and felt notwithstanding. The mantle is 

 much developed, forming two great irregular wing-like 

 lobes, which stand up on each side of the body, and at 

 pleasure either arch over the gill- shield, or are de- 

 pressed, and widely expose it. It is reported that these 

 mantle-lobes are capable of being used as swimmiiig- 

 fms, by their undulations ; but I doubt the correctness 

 of the observation. 



When full-grown, our Sea-hare is three inches in 

 length, and upwards of an inch high. Its body is of a 

 slimy, fleshy, slug-like texture, varying much in colour ; 

 sometimes being dark olive-green, sometimes red-brown, 

 sometimes deep purple, occasionally clouded with blue : 

 sometimes the hue is uniform ; at others, it is varied 

 by light dots, or handsomely marked with dark rings 

 enclosing white areas. Its figure is extremely versa- 

 tile ; so that, when crawling, it scarcely exhibits the 

 same outline for two minutes together. 



See what has happened. On dropping one of the 

 slimy beasts into this phial of clear sea-water, it imme- 



