LIMACINID^. 29 



Limacinidse, Gray^ Syn. Brit. Mus. 1840 ; Proc. Zool. Soc. 1847, 



203. 

 Limacinadae, Forbes ^ Hanley, Brit. Moll. ii. 379, 1849. 

 Pterobranchia, a, Gray, Lond. Med. Rep. 1821, 235. 

 Hyaleacea (part), Menke, Syn. 4, 1828, ed. 2, 8, 1830. 

 Hyaleae (part), Rang. Mon. 113, 1829. 

 Atlantarum (part), Deshayes, Ency. Meth. iii. 343, 1830. 

 Hyalidffi (part), D'Orb. Moll. Cuba, i. 70, 1841. 

 Limacinae (Les Limacines), part, Feruss. Fab. Sys. 25, 1821 (not 



Swainson, nor Blainv.) 

 Pterobranchia (part). Gray, Lond. Med. Rep. 1821. 

 Procephala (part), Lat. Fam. Nat. 1825. 

 Atlantidae (part.?), Gray, Proc. Zool. Soc. 1848, 149. 



These animals have been confounded, by D'Orbigny and others, 

 with Atlanta, which has a compressed foot with a sucker on the 

 hinder edge, a distinct head, and no lateral fins. 



Eschscholtz's figure of Steira (Isis, 1825, t. 5, f. 3) appears to 

 combine the two fins of Limacina with the head, tentacles, eyes, 

 and shell oi Atlanta. It is most probably only a bad figure of that 

 genus as it has not been observed by any succeeding zoologist. 

 He placed it in the same family with Limacina. 



1. LIMACINA. 



Animal elongate, spiral ; head indistinct ; mouth at the union of the 

 two fins and intermedial lobe, with two small labial swellings ; 

 fins 2, elongate, rounded, united at their base by an intermediate 

 semicircular lobe, bearing an operculum ; mantle large, open in 

 front, forming a large gill cavity ; gills in the mantle ; vent on 

 right side of mantle. — Shell univalve, spiral, sinistral, contain- 

 ing the animal ; operculum vitreous, thin, transparent, spiral, of 

 few whorls with a central muscular scar. (See DOrb. Amer. 

 Merid. t. 12, f. 24 and 39). 



Limacina, (helicinalis), Cuvier, Reg. Anim. iii. 1817; LamJc. Hist. 

 vi. 290, 1819, ed. 2, vii. 435; Schiveigger, Naturg. 750, 1820; 

 Gray, Lond. Med. Rep. 1821 ; Ferussac, Fab. Syst. 25, 1821 ; 

 Menke, Syn. 4, 1828, ed. 2, 8, 1830 ; D'Orb. Moll. Cuba, i. 70, 

 1841 ; Rang, Man. 113, 1829; Eschs. Isis, 1825, 735; Desk. E. 

 M. iii. 343; not Hartmann, 1821; nor Wiegmann, 1832; nor 

 Chray ; nor Sowerby, Genera, fig. so named is Atlanta. 



D 3 



