MOLLUSCA. 779 



Mollusca, with plates, &c., published by the Ray Society, London, 1845 

 1854, six parts, also QUATREFAGES in the Annales des Sc. nat. since 1843. 



A. Branchiae none. 

 Lissosoma KOELLIKER and QUATEEF. 



Limapontia JOHNST., Chalidis QUATREF. 

 Actceonia QUATREF. 



Phyllirhoe PERON. Body naked, compressed, with two very 

 long, subulate tentacles. (Organs of respiration unknown.) 



Comp. PERON Ann. du Mus. xv. p. 65, PI. n. figs, i 3; QUOT et 

 GAIMARD Voyage de V Astrolabe, Zoologie, n. 1833, pp. 403 410, PL 28, 

 figs. 10 18 ; [H. MUELLER und C. GEGENBAUER Ueber Phyllirhoe bucepha- 

 lum in KOELLIKER u. SIEBOLD'S Zeitschr. f. wissensch. Zool. v. 1854, pp. 

 355 37 1 > Taf ' XIX - PERON placed this animal as well as all the Hetero- 

 pods amongst the Pteropoda, LAMARCK amongst the Heteropoda, RANG 

 amongst the Salpce. ETDOUX and SOULEYET from the structure of the 

 animal first removed it to the Nudibranchiata. The form of the nervous 

 system, the pouch-like appendages of the intestinal canal, and the disposition 

 of the genital organs, all refer it to this division, although from the com- 

 pressed form of the body the foot be not distinguishable from the rest of 

 the integument. In the 2nd Edit, of his work VAN DER HOEVEN placed 

 gen. Phyttirhoe amongst the Heteropods. He now authorises its removal 

 to this place in the English Translat. of his Handbook. See the Anatomy 

 &c. in the mem. of MUELLER and GEGENB.] 



Cenia (previously Ictis) ALDER and HANCOCK. 



Note. Comp. on those genera destitute of branchiae, the synonymy of 

 which is very obscure, QUATREFAGES Mem. sur les Gasteropodes phlebentere's, 

 Ann. desSc. nat., 30 SeYie, i. Zool. pp. 129 183, and J. ALDEB and HAN- 

 COCK on a proposed new order of Gasteropodous Mollusca, Ann. of Natur. 

 History, sec. Series, i. 1848, pp. 401 415, PL 19, 20. Genus Pelta QUATREF. 

 if in reality it agrees with the Mollusc described by the English authors 

 A. and H. (Ann. of Nat. Hist, xviii. 1846, p. 289) cannot be united with 

 these dermatobranchiata or abranchiata. 



Actceon OKEN, Elysia E-isso, CANTRAINE. Body subcylindri- 

 cal, limaciform, bordered by a depressed expansion, acuminate 

 posteriorly. Two tentacles auriculate, subclavate, not retractile. 

 Two eyes behind the tentacles. Anus lateral, (sometimes middle, 

 posterior ?) on right side. 



Sp. Actceon viridis, Aplysia viridis MONTAGU, Linn. Trans. Tom. vn., QUATRE- 

 FAGES 1. 1. PL 3, fig. 2. Comp. OKEN Zool. i. 1815, p. 307, and especially 

 G. F. ALLMAN on the Anatomy of Actceon, Annals of Nat. Hist. Vol. 16, 

 1845, pp. 145162, PL 57. 



