THE DORIS. 



413 



sides of the animals. Many of these strange creatures are to be found on the British 

 coasts ; and if the reader should wish to gain a further insight into their habits, and to 

 examine the marvellous forms which the different genera assume, as well as their 

 exquisitely delicate and varied coloring, he is referred to the magnificent work of 

 Messrs. Alder and Hancock, published by the Ray Society. The entire structure of 

 the Nudibranchs is most curious and well worthy of examination, but is too purely 

 anatomical for admission into these pages. A few, however, of the more notable 

 structures will be mentioned in the course of our description. 



THE slug-like animal which is represented crawling on the frond of a laminaria, at 

 the left-hand of the engraving, is the common DORIS of our own shores. All the 

 members of the family to which this creature belongs may be known by the plume-like 



M 



CLAUCUS. Glaucus Paclflcus. 

 DORIS. Doris Johnston I. 



DENDRONOTUS. Deodronotus arborescens. 

 DOTO. Doto coroaata. EOLIS. Bolls coroaata. 



gills set in a circle on the middle of the back, like the feathery coronet with which the 

 Blackfoot Indian adorns the head of his horse, and the two tentacles placed more towards 

 the front. In the skin are imbedded a vast number of little spiculae. 



In the genus Doris both the tentacles and the gills can be drawn within the body at 

 the will of the animal ; and the mantle, which is pierced to permit the passage of the 

 gills and tentacles, is very large and covers the foot, as well as the whole upper surface. 

 All the nudibranchs are carnivorous, and feed chiefly on zoophytes. The sea- 

 anemones are favorite prey of these voraci >us creatures, and many an enthusiastic 

 naturalist has gained a knowledge of their habits at the expense of his special favorite ; 

 for whenever a nudibranch is placed in the same aquarium with specimens of actiniae 

 it is sure to attack them, eating great holes in their substance, and, if not removed, will 

 be as destructive as a hungry fox in a poultry-yard. 



THE next family is represented by two species, each of which will be briefly described. 

 In this family, called Tritonidas, the gills are arranged in lines along the sides of the 

 back, and the tentacles can be withdrawn into their sheaths. 



