780 CLASS XIII. 



Placobranchus V. HASS. 



Comp. VAN HASSELT in Bullet, univ. DE FERUSSAC, 1824, Oct. p. 240. 

 Scarcely distinct from the preceding genus, with which it is conjoined by 



B. ranchice external at the sides of back, numerous, tentaculiform. 

 t Vent posterior, in the middle of back. 



Janus VERANY, Antiopa ALD. and HANC. 



Comp. QUATREFAGES Ann. des Sc. not. 36 Serie, xi. 1849, PP- 7^ 9 

 PI. 3, 4. Sp. Janus Spinolce, Eolidia cristata DELLE CHIAJE. See also 

 Ann. of Nat. Hist. sec. Series, I. p. 190. 



Proctonotus ( Venilia previously) ALD. and HANC. 



Comp. ALDER and HANCOCK Annals of Nat. Hist. 13, 1844, pp. 161 

 164 and p. 407, PI. 2. Here also is to be referred as it seems genus Zephy- 

 rina QUATREF. [According to ALDER and HANCOCK the two differ in that 

 four linear tentacles are seen from above in Zephyrina, whilst in Proctonotus 

 the two larger are dorsal and the smaller arranged at the sides of the velum 

 which covers the head. Monograph. No. v. Procton.~\ 



ft Vent lateral, to the right. 

 Alderia ALLMAN. 



Comp. ALLMAN Ann. of Nat. Hist. Vol. 17, 1846, pp. i 5. 



Stiliger EHRENB. 

 Pterochilus ALDER and HANC. 



^Eolidia Guv. (^Eolis or Eolis auctor.). Tentacles four. 

 Angles of foot lateral, the anterior mostly produced. Branchiae 

 placed at the sides of back, numerous, tentaculiform, emitting 

 stinging filaments at the perforate apex. 



Sp. ^Eolidia papillosa, Limax papillosus L., Syst. not., BASTER NatuurJc. 

 Uilsp. i. Tab. x. fig. i, bl. 93, 94, Ann. of Nat. Hist. XV. PI. i. fig. i, 

 ALDER and HANC. Monog. Pt. vi. Fam. 3, PL 9 ; this little animal attains 

 a length of 2 inches. Comp. HANCOCK and D. EMBLETON on the Anatomy 

 of Eolis, Ann. of Nat. History, XV. 1845, pp. i 10, pp. 77 88, sec. 

 Series, i. 1848, pp. 88 105, FRET u. LEUCKART Beitr. z. Kenntniss wirbello- 

 ser Thiere, 1847, 8 - 54 64. The ccecal branches of the intestinal canal 

 are extended in the Eolidce into the branchial appendages. These appen- 

 dages have at the point a small vesicle, from whence filaments resembling 

 spermatozoa (nettle- threads, see above, p. 99) come to view. Ann. of Nat. 

 Hist. xv. PI. iv. PI. v. figs, i ii. 



In the neighbourhood of ^Eolidia some genera or sub-genera of later 

 authors may be placed, all of which cannot be noticed here. Eolidina, 



