LIMACINEA. 89 



apex, well defined by a striated sutural line, discoverable only 

 by the aid of a lens ; aperture oval, and very large, interrupted 

 above by the superior portion of the body ; outer lip thin, fre- 

 quently with a pale brown margin ; pillar lip slightly reflected, 

 and a little concave above. 



Subject to some variety both in form and colour ; but all I 

 have seen are only entitled to rank as one species. 



This species is found in all localities ; for I have met with it 

 in very moist situations, among decayed leaves, under stones, 

 &c., and I have procured specimens near the summit of 

 Arthur's Seat, at Edinburgh, eight hundred feet above the 

 level of the sea. It prevails all over Ireland, and Thompson 

 has found it in high mountain localities. 



I first observed this species in the cabinet of Mr. Dixon, of 

 Bishopwearmouth, in 1810, and drevi' and described it under 

 the name of Helix virides, as it was the green variety. I after- 

 wards met with the pale yellowish-white variety, in 1814, at 

 Farbane, King's County, Ireland. 



Genus XL— TESTACELLA— Cuvier. 



Shell very small, compressed, placed externally on the animal, 

 auriform; apex obsoletely spiral, consisting of less than two vo- 

 lutions; aperture very large, wide, and oblique; columella flat; 

 outer lip reflected, and thin, with a shght sinus behind. 



This singular univalve is found attached to the back of the 

 animal, near its posterior extremity. 



I. Testacella Haliotoidea, pi. IX, f. 24, 25. 



Testacella Haliotoidea, Drapernaud, p. 121, pi. 8, f. 44, 45 ; 

 Lamarck, An. San. Vert., VI, pt. 2nd, p. 52 ; Cuvier, An. du 

 Mus., V, p. 440, pi. 29, f. 6, 7 ; Thompson, Ann. and Mag. 

 Nat. Hist., VI, p. 19; Testacella scutidum, Sowerby, Gen. Rec. 

 and Foss. Sh., f. 3, 3; Testacellus Haliotoideus, Ferussac, Hist., 

 pi. 8, f. 5 to 9; Sowerby, Gen., f. 1, 2; Alder, Mag. Zool. and 

 Bot., II, p. 105 ; Testacella Europeea, Koissy. Buff"on, V, p. 

 252 ; Testacella Haliotoidea, Brown, Illust. Conch., p. 54, pi. 

 18,* f. 15, 16. 



Variety 1. Testacella scutulum, Sowerby. 



Shell auriform, ovoid, or elongated ; vertex rather large, 

 acute, placed at one extremity, and pointing to one side ; aper- 



N 



