ELYSIOIDEA. 



413 



Fam. 5. Proctonotidae. Anus posterior in the middle dorsal line. Anterior 

 tentacles atrophied. Janus Verany ; Proctonotus A. and H. 



Fam. 6. Fionidae. Liver as two longitudinal canals, into which open the 

 caeca of the cerata. Fiona Hancock and Embleton. 



Tribe 4. ELYSIOIDEA (SACCOGLOSSA). 



Liver branched, the branches generally extending into cerata. Genital ducts 

 usually triaulic, with widely separated genital openings. The vaginal orifice 

 is, in some cases at any rate, developed later than the other two openings. 

 Without jaws. Radula with one series of strong teeth, the worn-out teeth at 

 the front end not dropping off, but preserved in a special sac (Ascoglossa Bergh). 

 The pedal ganglia are near together, and the visceral commissure has three 

 ganglia almost in contact. 



FIG. 328. Aeolis pnpillosa 

 (after Alder and Hancock). 

 Rp dorsal papillae (cerata). 



FIG. 329. Section of a dorsal 

 papilla of Eolis x,40. a ter- 

 minal sac which produces 

 nematocysts; b ectoderm; c 

 hepatic caecum; d tube con- 

 necting the caecum with the 

 terminal sac ; e opening of th 

 sac (after Pelseneer). 



FIG. 330. A neinato- 

 cyst wi.th pro- 

 truded thread of 

 Aeolis punctata]x 

 500 (from Pelse- 

 neer, after Vays- 

 siere). 



Fam. 1. Hermaeidae. Cerata in several rows ; anus dorsal. Hermaea 

 Loven, Stiliger Ehrb., Phyllobranchus A. and H., Cyerce Bergh, hepatic caeca 

 do not extend into cerata ; Alderia Allmaii. 



Fam. 2. Elysiidae. Cerata absent ; dorsal integument forms two lateral 

 expansions containing hepatic caeca. Anus lateral. Reno-pericardial openings, 

 numerous. Elysia Risso, 



