Freshwater Mollusca of Ireland. 



27 



hardly differs more from the ordinary state of H. hispida than the 

 specimens of it common to the North of Ireland do, and ■which are 

 considered by Mr. Alder and M. Michaud only varieties of the spe- 

 cies bearing this name. I cannot look upon it otherwise than as a 

 var. of H. hispida. 



13. Helix hispida, Mull. Gray, Man. p. 154.* pi. 4. f. 41 ; Turt. 

 Man. p. 57. f. 41. 



This species is generally distributed over Ireland. It is one of the 

 most common land shells in the North, and may be found under 

 stones, fallen trees, decaying leaves, &c. from the sea- shore to the 

 most elevated chalk districts, and both in moist and very dry situ- 

 ations. It is most variable in colour; from beneath the same stone 

 I have procured specimens varying from a crystalline transparency 

 to dark reddish brown, and in these differences the animal partici- 

 pates with the shell ; like H. rufescens, Mont, and some other species, it 

 occasionally presents a white band on the last volution ; in the very 

 youngest state this species is hispid, and quite depressed or flat 

 above. The internal rib, in what to distinguish it from H. con- 

 cinna, may be called the normal state of H. hispida, which I find in 

 the North is generally wanting ; on supplying Mr. Alder with spe- 

 cimens of these in April 1S36, he observed that they were the most 

 strongly marked varieties he had seen ; and about the same time, 

 M. Michaud, in acknowledging specimens I had sent him, remarked 

 upon them as a very fine variety of H. hispida. The shells thus al- 

 luded to are of the most common form in the North of Ireland ; and 

 are larger, more depressed, and with the umbilicus comparatively 

 wider than in specimens which I have found in various parts of En- 

 gland and Scotland, and which are similar to those that under the 

 name of H. hispida have been sent me from Newcastle by Mr. Alder 

 and from Lorraine f by M. Michaud ; specimens the same as the En- 

 glish and French are likewise to be met with in the North of Ire- 

 land, but are rare comparatively with the others. 



Note. — Sept. 17, 1837. On looking to the animals of full-grown 

 specimens of this Helix collected at Wolfhill near Belfast, I could 

 not perceive any difference between the inhabitants of the very his- 

 pid shells wanting the internal rib, and those having the rib and dis- 

 playing very few hairs — the animals are commonly pale grey above 

 and whitish beneath ; in the very hispid shells they varied from this 

 colour to black. 



14. Helix concinna, Jeff. Gray, Man. p. 154. pi. 12. f. 135. 



The shell alluded to under this name is that described by Mr. 

 Alder, as " stronger, and with the hairs more deciduous than the 

 usual form [of H. hispida']," Mag. Zool. and Bot. vol. ii. 107, and 

 which I would add is generally more convex, and has an internal rib, 



* The four wood-cuts in this page are very characteristic, 

 t The specimens, eight in number, from this locality, want the internal 

 rib. 



