246 CLASS VII. 
Aphrodita 1. (exclusive of some species), Halithea Sav. Head 
concealed under squamz or sete, furnished with two pedunculate 
eyes and three tentacles. Jaws small or none. Branchie and 
dorsal cirri in feet destitute of squama, which alternate with squa- 
miferous feet. Body oval, depressed. 
* Dorsal squame naked. 
Sp. Aphrodita hystrix, Halithea hystria Sav., AuD. and Epw., Ann. des Se. 
nat. XXvIl. Pl. 7, figs. i—9. 
** Dorsal squame covered by a stratum of villose sete. 
Sp. Aphrodita aculeata L., Baster, Natwurk. Vitsp. Tab. vi. figs. 1, 2, PALL. 
Misc. Zool. pp. 77, &c. Tab. vit. figs. 1—13 ; Physalus SWAMMERD. Bibl. 
nat. Sea-Mouse. Ordinarily five or six inches long and an inch and a half 
broad. ‘The hairs on the two sides of the body are glistering, green and 
red, or playing with all the colours of the rainbow ; the back is clothed 
with a felty covering, that consists of interwoven hairs. When this 
covering is opened, five nearly circular plates (squame, elytra) are seen on 
each side, which partially cover each other, and of which the middlemost 
are the largest. If two consecutive plates be separated, there are seen on 
the ring that lies between them, small longitudinal nodes, which are parted 
by a pit, and are provided outwards and backwards with pectinated 
appendages as though torn at the margin (the gills). In the Atlantic 
Ocean, the Mediterranean, &c. 
Note.—The genus Sagitta SLABBER, Quoy and GAIM., whose 
place is uncertain, seems to approximate closely to the Annulata. 
Body not annulate, elongate, pointed at both extremities, supplied 
with lateral pinne and a terminal truncated pinna; head distinct 
from the body by a neck, with two eyes, and horny teeth on both 
sides. All the individuals hermaphrodite. 
Comp. A. Kroun Beobachtungen ueber die Sagitta bipunctata, Hamburg, 
1844, 4t0; R. WILMS, Observationes de Sagitta, Berolini, 1846, 4to. 
