30 LIMAPONTIID.^. 



water, Hylton Dene, near Sunderland (A. Hancock) ; Loughor 

 Marsh, near Swansea (Bate, Jeffreys, and Moggridge). 



This species is distinguished from the last by its much 

 greater size, more depressed form, and wider lateral expansion, 

 as well as by the more backward position of the vent. The 

 Limapontia figured by Mr. Spence Bate in his ' Xotes on the 

 Fauna of Swansea and the Neighbourhood' (1849) evidently 

 belongs to this species, not only from its size and form, but 

 also from the more branched character of the hepatic organ, 

 as shown in figures 5 and 6. 



Genus II. ACTEO'NIA^ Quatrefages. 



Body liniaciform, with a slight ridge on each side of the 

 back : head subangulated : tentacles 2, more or less developed, 

 rising from a carina on each side of the head : vent dorsal, 

 situated two-thirds down the back : odontojjJwre having a 

 single row of spines. 



1. AcTEONiA corruga'ta^ Alder and Hancock. 



A. cornigata, A. & H.in Ann. N. H. 2nd ser. i. p. 403, pi. 19. f. 2, 3. 



Body nearly linear, rather short and stout, regularly wrinkled 

 in a longitudinal direction ; black, excepting the carina and 

 tail, which are whitish: head carinated at the sides, each 

 carina being produced into a short, flat, whitish, tentacular 

 process : eyes placed in circular white spots behind the cariuae : 

 there is a slightly raised ridge on each side of the back in the 

 region of the vent. L. 0*12. 



Habitat : Rare ; found by Mr. Cocks at Falmouth feeding 

 upon Conferva glaucesceiis in company Avith Limapontia nigra. 



2. A. CocKsii, Alder and Hancock. 



Ccnia Cocksii, A. & H. in Ann. N. H. 2nd ser. i. p. 404, pi. 19. f. 1. 



Body robust, smooth, considerably elevated on the back ; 

 black above, fading into fawTi colour at the sides : head slightly 



* From Act(B07i, a synonym of Elysia. 



