246 CLASS vii. 



Aphrodita L. (exclusive of some species) , Halithea SAV. Head 

 concealed under squama? or setse, furnished with two pedunculate 

 eyes and three tentacles. Jaws small or none. Branchiae and 

 dorsal cirri in feet destitute of squama, which alternate with squa- 

 iniferous feet. Body oval, depressed. 



* Dorsal squamw naked. 



Sp. Aphrodita hystrix, Halithea hystrix SAV., AUD. and EDW., Ann. den V. 

 not. xxvn. PI. 7, figs, i 9. 



* * Dorsal squamae covered by a stratum of villose setae. 



Sp. Aphrodita aculeata L., BASTER, NatuurTc. Uitsp. Tab. vi. figs, i, 2, PALL. 

 Misc. Zool. pp. 77, &c. Tab. vn. figs, i 13 ; Physalus SWAMMERD. Bibl. 

 not. Sea-Home. 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 (squama, 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 pinnae 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, 4to; R. WlLMS, Observations de Sagitta, Berolini, 1846, 4to. 



