NUDIBRANCHS. 341 



The beautiful branched gills are set in a very shrub-like fashion upon the back, and even the 

 tentacles and appeudages of the head are branched so as to correspond with the gills. 



The Dendronotus is common in the waters along the New England coast. It is one of the 

 finest, most showy of the race in this region, and forms a pleasing inmate of the aquarium. 

 Our illustration gives the size of the American form. 



6* 



Our next example is the beautiful Doto. It may be here remarked that the word Doto 

 is the name of one of the sea nymphs of mythology, and that in consequence of their exquisite 

 coloring and beautiful forms, the names of nearly all the nymphs have been given to different 

 species of nudibranchs. The tentacles of this animal are slender, and can be retracted into 

 certain trumpet-like sheaths, which are seen projecting from the body. In this creature the 

 processes of the digestive system pass into the large appendages on the back ; and it is a 

 curious fact that, although they fall off when the animal is handled, they are soon repro- 

 duced, and the creature seems to suffer little inconvenience from their loss. Examples of 

 this creature can be found on the European coasts. 



Of the family Dotonidce, the Doto coronata is common, inhabiting the same localities as 

 the preceding forms — Nahant, Back-bay, and Beverly Beach. It is equally common in Europe. 



Another family is f ormed by the Eolidse. In these creatures the theory of i>hlebenterism 

 finds its best proofs, as the processes of the digestive organs extend throughout the beautiful 

 projections on the back, even though, as in one genus, they are placed on footstalks. 



The beautiful Eolis is common on the coasts of Europe, and has often been seen moving- 

 over the plants and stones with tolerable activity, and always keeping its tentacles and papilla 

 in motion, sometimes contracting and sometimes extending them, while the movement of the 

 water causes it to wave in a very graceful manner. These papilla possess the property of 

 discharging a milky kind of fluid when the animal is irritated. The fluid, however, is quite 

 harmless, at all events to the human skin. As in the previous case, the papilla? are liable to 

 fall off at a touch. While using the dredge, the naturalist is sure to bring plenty of nudi- 

 branchs to the surface ; but owing to their habit of contracting themselves into a shapeless 

 mass, an uninitiated observer vail probably fail to notice them, and fling them overboard 

 again, together with the sea-weeds, stones, and other refuse substances. The Eolis is a voracious 

 being in spite of its delicate beauty, and if several of them are kept in a vessel and not 

 supplied with the sertularia and other zoophytes on which they feed, they will attack and 

 devour each other. 



Family Eolidce is represented in American waters by Eolis papillosa ; found in same 

 localities as the last. It is one of the most common species in northern seas. Several 

 beautiful species are found in the usual places — Boston, Back-bay, Beverly, Nahant, and 

 Lynn. Eolis dostoniensis is a notable one, and the salmon-colored species. 



The last and most remarkable example of the nudibranchs is the Glaucus, or Sea 

 Lizard, a strange-looking creature. In this animal the gills are slender, cylindrical, and 

 supported on three pairs of lobes or footstalks. 



The Sea Lizard is very common in many parts of the Atlantic, where it is found in vast 

 numbers during a calm and when the sea is smooth. Mr. F. D. Bennett writes as follows about 

 this strange and eccentrically formed being: "These creatures obtain in greatest number where 

 currents most prevail ; they are active and very predatory in their habits, and would appear, 

 from the observations of my brother, which I have already confirmed, to subsist chiefiy upon 

 the soft parts of the defenceless genera Velella and Porpita. The specimens we captured and 

 kept in sea-water contracted their bodies into many convulsive attitudes, but seldom employed 

 their branchial fins, and floated buoyantly while passive. When immersed in fresh water 

 they contracted themselves into a very small compass, assumed a globular form, cast the 

 tentacles from off their branchial fins, lost their color, and expired in a very few moments." 



Super-order Anisopleura now (1885) embraces the largest division of the Gasteropods. 

 The naked mollusks are of them. Nudibranchs, so called because their respiratory organs 



