FAMILY AURICULID^ II5 



by which Semper associated the occurrence of dorsal eyes in Onchi- 

 dium with the presence of the fish Periofthalmus . There are both 

 oculiferous and (dorsally) blind species of Onchidium in the Gala- 

 pagos, and an oculiferous species in Florida and Bermuda, and in 

 neither of these regions is Periopthalmus known. It is of course not 

 only necessary that an hypothesis should account for the facts, but that 

 it also should be true, but the latter half of the proposition is only too 

 liable to be left unverified. 



Family AURICULID^. 

 Genus Carychium Miiller. 



Carychium O. F. Muller, Hist. Verm., 11, p. 125, 1774 ; sole ex. C. mini- 

 mum MvlWqx \ Zool. Dan. Prodr., p. xxix, 1776. — Draparnaud, Hist. 

 Moll. Terr., p. 57, 1805 (in synonymy). 



Helix (sp.) Gmelin, Syst. Nat., vi, p. 3665, 1792. 



Bulimus (sp.) BRUGUifeRE, Encyc. Meth., i, p. 310. 



Turbo {s^.^ Montagu, Test. Brit., p. 339. 



Auricula (sp.) Draparnaud, Talsleau des Moll., p. 54, 1801 ; Hist., p. 57, 

 pi. Ill, figs. 18, 19, 1805. 



Odostomia (sp.) Fleming, Edinb. Encycl., vii, p. "jS, 181 7. 



yi«nV(?//a(BRARDMS.)JuRiNE, Hclvet. Almanach, p. 34, 1817. — Hartmann, 

 in Steinmiiller, Neue Alpina, i, pp. 49, 205, 215, 1821 ; and Sturm, 

 Fauna, vi, heft v, p. 36, 1821 ; Syst. Uebersetz., table, 1840. — 

 MoQUiN Tandon, Hist. Moll. Terr. Fr., 11, p. 413, 1855. Type C. mini- 

 mum Muller. 



Auriculina Moquin Tandon, Hist. Moll. Terr. Fr., 11, p. 646, 1855 ; not of 

 Grateloup, 1838, nor Gray, 1847. 



Saraphia (sp.) Risso, Hist. Eur. Men, iv, p. 84, 1826 ; S. tridentata Risso. 



< Carychium Leach, Zool. Misc., I, p. 85, 1814. — F^russac, Prodr., p. 100, 

 1819 ; Tabl. Syst., p. xxxiii, 1821. — Blainville, Diet. Sci. Nat., viz, p. 

 187. — MoQuiN Tandon, Hist. Moll. Terr. Fr., pp. 412, 413, 1855. 



Fig. 83. Carychium exiguutn Say. Animal and shell magnified. 



The species of this genus are so small that a special search almost 

 is necessary to determine their presence or absence in a given locality. 



