208 MANUAL OF THE MOLLUSCA. 



Animal with 4 long tentacles, mantle with a siphonal process ; foot ex- 

 panded, truncated in front, furnished with a float after the manner of 

 lanthina ; lingual dentition closely resembling Jeffreysia. 



Distr. 2 sp. Taken in the towing-uet off C. Byron, E. coast Australia, 15 

 miles from shore; floating, and apparently gregarious. (J. MacgiUivray.) 

 Mindoro. (Adams.) 



SECTION B. Gymnosohata, B1. 



Animal naked, without mantle or shell ; head distinct ; fins attached to 

 the sides of the neck ; giU indistinct. 





J 



EAMILY III. Cliid.^. 



Body fusiform; head with tentacles often supporting suckers; foot small, I 

 but distinct, consisting of a central and posterior lobe ; heart oplstho-bran- ! 

 chiate ; excretory orifices distant, on the right side ; lingual teeth (in Clio) i 

 12.1.12j central wide, denticulated, uncini strongly hooked and recurved. : 



Clio (L.)* MuUer. d 



EUjM. Clio, a sea-nymph. Sijn. Clione, Pallas. 'S 



Type, C. borealis, PI. XIV. fig. 45. (C. caudata, L. part.) j 



i/^af/with 2 eye tubercles and 2 simple tentacula; mouth with lateral J 

 lobes, each supporting 3 conical retractile processes, furnished with numerous J 

 microscopic suckers ; fins ovate ; foot lobed. In swimming, the Clio brings \ 

 he ends of its fins almost in contact, first above and then below. {Scoresby.) \ 

 Distr. 4 sp. Arctic and Antarctic Seas, Norway, India. 

 Suh -genus ? Cliodita (fusiformis), Quoy and Gaimard. Head supported 

 on a narrow neck ; tentacles indistinct. 3 sp. Cape, Amboina. 



Pneumodermon, Cuvier. 



Etym. Pneumon, lung (or gill), derma, skin. f 



Type, P. violaceum, PI. XIV. fig. 46. 



Body fusiform ; head furnished with ocidar tentacles ; lingual teeth 

 4.0.4 ; mouth covered by a large hood supporting two small, simple, and two 

 large acetabuliferous tentacles, suckers numerous, pediciUate, neck rather 

 contracted ; fins rounded ; foot oval, with a pointed posterior lobe ; excretory 

 orifice situated near the posterior extremity of the body, which has small 

 branchial processes and a minute, rudimentary shell. 



* This name was emploj-ed by Linnseus for all the Pteropoda then known ; his 

 definition is most suited to the "northern clio," probably the only species with which 

 he was personally acquainted. The first species enumerated in the Syst. Nat. is 

 C. caudata, and reference is made to an indeterminable figure in Brown's Jamaica, 

 and to Marten's account of the Spitzbergen moUusk (C. borealis.) In cases like 

 this the rule is to adopt the practice of the next succeeding naturalist who defines 

 the limits of the group more exactly. 



