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. Branchie none. 
Liissosoma KoELLIKER and QUATREF. 
Limapontia Jounst., Chalidis QUATREF. 
Acteonia QUATREF. 
Phyllirhoe Peron. Body naked, compressed, with two very 
long, subulate tentacles. (Organs of respiration unknown.) 
Comp. Péron Ann. du Mus. xv. p. 65, Pl. mW. figs. 1—3; Quoy et 
GaAIMARD Voyage de l Astrolabe, Zoologie, 11. 1833, pp. 403—410, Pl. 28, 
figs. r1o—18 ; [H. MUELLER und C. GEGENBAUER Veber Phyllirhoe bucepha- 
lum in KOELLIKER u. SIEBOLD’S Zeitschr. f. wissensch. Zool. Vv. 1854, pp. 
355—371, Taf. xix. Péron placed this animal as well as all the Hetero- 
pods amongst the Pteropoda, LAMARCK amongst the Heteropoda, Rane 
amongst the Salpe. Eypoux and SouLEyEr 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 HorvEN placed 
gen. Phyllirhoe 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 Jct’s) ALDER and HANcocK. 
Note.—Comp. on those genera destitute of branchiz, the synonymy of 
which is very obscure, QUATREFAGES Mém. sur les Gasteropodes phlebentérés, 
Ann. des Se. nat., 3e Série, 1. Zool. pp. 129—183, and J. ALDER and Han- 
COCK on a proposed new order of Gasteropodous Mollusca, Ann. of Natur. 
History, sec. Series, 1. 1848, pp. 4o1—415, Pl. 19, 20. Genus Pelta QUATREF. 
if in reality it agrees with the Molluse described by the English authors 
A. and H. (Ann. of Nat. Hist. xvi. 1846, p. 289) cannot be united with 
these dermatobranchiata or abranchiata. 
Acteon OKEN, Elysia Risso, CANTRAINE. Body subcylindri- 
cal, limaciform, bordered by a depressed expansion, acuminate 
) , Ye eR Pp 
posteriorly. Two tentacles auriculate, subclavate, not retractile. 
Two eyes behind the tentacles. Anus lateral, (sometimes middle, 
posterior ?) on right side. 
Sp. Acton viridis, Aplysia viridis Montaau, Linn. Trans. Tom. vit., QUATRE- 
FAGES 1. 1. Pl. 3, fig. 2. Comp. OKEN Zool. I. 1815, p. 307, and especially 
G. F. ALLMAN on the Anatomy of Actwon, Annals of Nat. Hist. Vol. 16, 
1845, pp. 145—162, Pl. 5—7. 
