v.vu, ,.•..' MoUusca of Great Britain. 385 



Testa supr^ umbilicatula, subtiis convexiuscula, vix per- 

 forata, utrinque in carinam acutam obliquata, lateri- 

 bus subinaequalibus, tenuis, substriata, flavescens. An- 

 fractm 6, subdepressi. Apertura angulata. 

 Long. 0.2. — Diam. 0.65. 



Planorbis carinatus. Miill, Verm. 2. p. 157. Drop. 



Hist, des Moll. p. 46. t. 2. /. l6. 

 Helix Planorbis. Linn. Syst. Nat. 1. p. 1242. Gmel. 



St/St. Nat. I. p. 3617. 



complanata. Mont. Test. Brit. p. 450. t. 25./. 4. 



planata. Maton Sf Rackett in Linn. Trans. 8. 



p. 189. <. 5./. 14. 



In ditches, &c. ; but I have never found it mixed with 

 the last. 



7. LUTESCENS. 



Animal pallide flavescens. Tentacula pellucida. {Mo7it.) 

 Testa dilatata, vald^ depressa, supr^ umbilicatula, sub- 

 perforata, subtils convexiuscula, utrinque in carinam 

 acutam prominulam obliquata, lateribus sequalibus, 

 fragilissima, hyalina, glabra, albido-lutescens. Anfrac- 

 tus 4 vix 5. Apertura acuta, angulosa. 



Long. 0.125. — Diam. 0.5. 



Planorbis lutescens. Lam. Hist, des Anim. sans Vert. 6. 



p. 153. 

 Helix carinata. Mont. Test. Brit. p. 451. t. 25./. 1. 

 Planorbis. Dillw. Cat. 2. p. 896. 



In stagnant pools in some of the midland counties of Eng- 

 land ; often mixed with the last, but much less common. 



Schroter has noted all the three last species, though, as 

 is evident from his referring his figure of the Planorbis ca- 



3 D 2 rinatus 



