554 APLYSIADJ^. 



The sea-hares live among sea-weeds iu the Laminarian 

 zone, rarely straying out of that region. They feed on 

 both vegetable and animal matter, as was observed by 

 Cuvier, though, by some mistake, his authority has fre- 

 quently been quoted for the statement that they are exclu- 

 sively vegetable feeders. They breed in spring, and lay 

 their eggs in slimy nidi among sea-weeds. At their breed- 

 ing season they often congregate in vast numbers. 



The anatomy of the Ajjfysi^e forms the subject of one of 

 Cuvier's most admirable memoirs, and some new and most 

 interesting inquiries into their circulation have been pub- 

 lished by Milne-Edwards in his account of zoological 

 researches in Sicily. 



Three species of Aplysia are usually enumerated as in- 

 habiting the British seas. We can obtain no authentic 

 evidence of more than one having been observed, for the 

 so-called depilans is not that species, but a variety of the 

 following, of which nexa proves to be the young animal. 



A. HYBRiDA, Sowerb}'. 



Plate CXIV. F. fig. 4, and (Animal) Plate Y. Y. fig. 1. 



Laplysia depilans. Pennant, Brit. Zool. ed. 4, vol. iv. p. 42, pi. 21, f. 21. 

 Aplysia hyhrida, Sowbrby, Brit. Misc. pi. 53 (1806). 



,, mustelina, H. Da vies in Pennant Brit. Zool. ed. 1812, vol iv. p. 79, 

 pi. 22. — Johnston, Trans. Berwick. Nat. Club, vol. ii. p. 29. 



„ depilans and punctata, Fleming, Brit. Anim. p. 290. 



„ nexa (young), Thompson, Ann. Nat. Hist. vol. xv. p. .313, pi. 19, f. 8. 



,, dfpilans, Brit. Marine Conch, p. 1 43, f. 80. 



,, pujictata. Alder, Cat. Moll. Northumb. p. 24. 



In our synonymy of the only British species of Aplysia 

 at present known with any certainty, we have abstained 

 from referi'ing to the figures and descriptions of continental 



