114 PNEUMONOBRANCHIATA. 



Shell about six lines long and four broad, thin, 

 semi-transparent, yellowish-white, concave on the 

 inside, which is sometimes sprinkled with minute 

 crystal-like shining particles, a little convex and 

 transversely wrinkled on the outside ; with the edges 

 membranaeeous ; on the top, or broader extremity, 

 is a small central prominence, or apophysis of ad- 

 hesion, by which it is attached to the animal ; the 

 lower extremity very thin and rounded. 



When irritated, they dilate their shields. Their eggs 

 are white, and deposited in spring under stones, &c. 



These animals (especially the larger slug) are often 

 infested with mites, which were discovered by Reaumur, 

 in the Mem. Acad. des Sciences, 1710, and called by 

 Gmelin Acarus Limacum. They have been well de- 

 scribed, with some interesting details of their habits, 

 by Mr. Jenyns, under the name of Philodromus 

 Limacum, in the Mag. Nat. Hist. iv. 538. f. 109. 



* * Mantle short and rounded behind ; shell flat. 



12. 2. LIMAX flavus. Yellow Slug. Yellowish, 

 tessellated with brown; tentacles bluish; the 

 hinder part of the mantle rounded ; shell thin, 

 concave, mammillated externally at its posterior 

 extremity, (t. 5. f. 16.) 



Limax flavus. Linn. Fauna Suec. 363. 



variegatus. Drap. Hist. Moll. 127.; Fer. 



Prod. 21., Hist. 71. t. 5. f. 16. ; Nunneley, 1. c. 

 47. t. 1. f. 3. ; Leach, Brit. Mus. 



Yellow Slug. Penn. Brit. Zool. iv. 41., from Lister. 



Limax succino colore. List. Conch, t. 101. f. 6. 



Limacella concava. Brard, 121. t. 4. f. 5, 6. 13, 

 14, 15. (Shell.) 



