94 GASTEROPODA. 



Genus l.—YlTRllSiA.—Lamarck. 



Geneiic Character. — Body creeping, elongated, snail-shaped, 

 nearly straight ; posteriorly separated from the foot, and spirally 

 wound into a shell ; the various posterior appendages of the 

 mantle displayed over part of the shell ; four tentacula ; the 

 anterior very short. Shell small, extremely thin, depressed, 

 spire very short ; body very large ; aperture ample, rounded and 

 oval ; the left margin slightly inflected. 



Vitrina pellucida The Pellucid Vitrina. Plate XIII. 



fig. 5. Extremely thin, pellucid, and glossy ; depressed, with 

 the spire very short ; of a pale yellowish green ; aperture large 

 and oval. Four lines long. Inhabits dry places of Europe. 



Gems 2 TEST ACELL A.— Lamarck. 



Generic Character. — Body creeping, elongated, snail-shaped, 

 having a shell on the posterior extremity; four tentacula^, the 

 two longest with their eyes at their tips ; vent and respiratory 

 organs behind. Shell very small, external, — somewhat ear- 

 shaped ; the apex obsoletely spiral ; aperture very large, oval, 

 with outer lip inflected. 



Testacella Haliotidea. — The Haliotis- Shaped Testacella. 

 Plate XIII. fig. 23. Shell oblong-ovate, auriform ; left mar- 

 gm slightly reflected ; exceedingly thin, transparent, and yellow- 

 ish. Inhabits the middle provinces of France. 



Genus 3.—hlMAX.—Linnceus. 



Generic Character.— Body oblong, naked, and creeping ; back 

 convex, provided with a coriaceous slightly wrinkled shield, 

 which has a flat longitudinal disk beneath ; tentacula four, re- 

 tractile, the two posterior the largest, with eyes at their tips ; 

 branchial cavity placed under the shield ; orifice for respiration 

 and vent on the right side. Shell small, extremely thin, oblong, 

 ovate, not convolute, but with a cavity at top. 



Limax Rnfus The Red Limax. Plate XIII. fig. 29. 



Shell ovate-oblong, both margins reflected ; very thin^ dia- 



