228 The Irish Naturalist August, 



Dr. Simroth emphasises the great divergence in their organisa- 

 tion and avows that he would not hesitate to use these 

 differences to recast and rearrange the grouping of the species. 

 Jltri?ia elongala belongs to the group named Semilimax, so 

 named on account of the decreasing size of the shell relatively 

 to the animal, and the creature's increasing affinity to the slugs, 

 while our other species, V. pellacida, is referred to Phenacolimax 

 or Helicolimax, the latter name expressing its greater similarity 

 to the Helices. 



Vitri?ia eh?igata is an old established, well marked, and 

 universally recognised species, described and named by 

 Draparnaud at the beginning of last century, and its claim 

 to specific distinction has, I believe, never been challenged. 



Viirina elongata has several synonyms, and has been placed 

 in at least six different genera by authors. 



1802. Helix semilim ax, Fer., Natwforsch. xxix.. St. p. 236, 



pi. 1 f. A.— D. 

 1805., Vitrina elongata, Drap., Hist. Moll., p. 120, pi. vii., 



ff. 40-42. 

 1 815. Testacdla germanice, Oken., Lehrb. Nat., iii., p. 312. 



1820. Hyalina elongata, Hartm., in Stud., Kurz. Verzeichn., 



p. 86. 



182 1. Limacea vitrea var. /3. Hartm., in Neue Alp. i., 



p. 246. 



1822. Helicolimax elongata^ Fer., Tabl. Syst., p. 25, et Hist , 



pi. ix., f. 1. 



The animal is considerably larger than the shell it bears, 

 and cannot withdraw within the shell for shelter ; it is very 

 elongate and slender in form, and may attain a length of 15 

 mill. ; the body is of somewhat pellucid grey, paler on the head 

 and neck than in V. pellncida. The shield or mantle is also of a 

 clear grey with jet black marblings, and is transversely some- 

 what concentrically striate ; the spatuliform lobe on the right 

 side of the body is marked like the shield, and extends 

 beyond and covers the apex of the shell ; the respiratory 

 orifice is rather large, and is placed at the base of the 

 spatuliform lobe ; the ommatophores are rather stout, 

 thickened basally, and bulbous at the extremities, where the 

 small, black eye-specks are placed. The tail is very acute, 



