302 THE ZOOLOGIST. 



cone at the point from which the thread issues, and here slightly 

 dimpling the surface of the water."* It appears, from an 

 observation by Gray on Elysia, that the suspensory thread can 

 be subsequently ascended by the animal. 



Polycerid^. 



Thompson states that three Sea-Slugs believed to pertain to 

 Polycera quadrilineata,\ kept in a phial of sea- water, were gener- 

 ally seen suspended by their threads from the surface, the body 

 at the same time moving freely about with much grace. % Polycera 

 lessonii, Alder and Hancock mention, may be seen, in captivity, 

 for hours together, " suspended by a film of raucous matter from 

 the surface of the water." 



Doridid^. 



Chromodoris amabilis§ (Ceylon), according to Kelaart, some- 

 times creeps at the surface, and " when touched with a feather it 

 adheres by its foot, and can be kept dangling in this position by 

 the aid of the mucous thread secreted by the surface of the foot."|| 



Eolididje. 

 Mr. Sinel mentions having frequently observed Eolis hanging 

 by a thread from the water-surface, the suspended animal having 

 the body doubled up, Hedgehog-like, with the back downwards.1T 

 The writer learns from Mr. Hornell that the animal thus referred 

 to by his colleague is Facelina coronata.** The thread, Mr. 

 Hornell states,tt is sometimes 4-5 in. in length. 



Elysiid^:. 

 Elysia viridis,U from Swanage Bay, kept by Gray in a vase, 

 usually rested, attached by the tail to the glass, with the body 



* Alder and Hancock, op. cit. p. 21. 



f P. quadrilineata v. nonlineata. 



J Thompson, ' Annals of Natural History,' v. (1840), p. 92. 



§ Doris amabilis. 



II Kelaart, 'Annals and Magazine of Natural History' (3), hi. (1859), 

 pp. 294-5. 



II Sinel, ' Journal of Marine Zoology,' i. (1894), p. 32. 

 ** Eolis coronata. 



ft Hornell, 'Journal of Marine Zoology,' ii. (1896), p. 59. 

 || Aplysiopterusviridis. 



