194 Mr. W. Thompson's Catalogue of the Land and 



Thus the group Fringillinae has six subdivisions ; Pyrrhulinae 

 has six ; Meliphagidae nine ; Tetraonidae six ; Ardeadae six, or 

 including Grus (which is apparently omitted through inad- 

 vertence), seven ; and Alcadae has six. 



I feel bound to state, that, notwithstanding these objections, 

 the ' Classification of Birds ' is an exceedingly useful manual 

 of ornithology, and it must be regretted that the mass of ori- 

 ginal observations which it contains is intermixed with so 

 much that is of a visionary nature. 



Note. — The questions which are the subject of the above paper were dis- 

 cussed at much length in the Philosophical Magazine, in 1823 and 1825. 

 The reader is referred to vol. lxii. p. 192, 255, 274; vol. Ixv. p. 105, 183, 

 372, 428; vol. lxvi. p. 172: also to Phil. Mag. and Annals, New Series, 

 1830, vol. vii. p. 431 ; vol. viii. p. 52, 134, and 200.— Ed. 



XXIV. — Catalogue of the Land and Freshwater Mollusca of 

 Ireland. By Wm. Thompson, Vice-President of the Na- 

 tural History Society of Belfast. 



[Continued from p. 126.] 



Class II. CONCHIFERA, Lam. 



Fam. 1. Cyclad^:. 



Gen. 1. Cyclas, Lam. 



1. C. comea-f Lam. Gray, Man. p. 280. pi. 1. f. 2 ; Turt. Man. p. 



13.pl. l.f. 2. 

 C. rivalis, Drop. p. 129. pi. 10. f. 4, 5. 

 Cardium corneum, Mont. p. 86. 

 Commonly distributed over the island, occurring in small ponds, 

 &c, as well as lakes and rivers — the var. j3. of Jenyns and other va- 

 rieties not unfrequent. In summer I find the C. cornea of all sizes 

 abundant in masses of Conferva, floating on the surface of the water. 



2. Cyclas lacustris, Turt. Gray, Man. p. 281. pi. 1. f. 3. 



C. calyculata, Drap. p. 130. pi. 10. f. 13, 14 ; Turt. Man. p. 14. 

 f. 3. 



Cardium lacustre, Mont. p. 89. 

 Is rare and local in Ireland — occurs in the east and south. To 

 Mr. R. Ball of Dublin, I am indebted for specimens which were taken 

 by him many years ago in a pond at Tallaght, a few miles from the 

 metropolis ; he has also procured some at Youghal — in Mr. Hynd- 

 man's cabinet is a specimen from another locality in the south. By 

 Mr. T. W. Warren of Dublin, this Cyclas has been obtained in a 

 pond in the Phoenix Park, and in the Grand Canal near that city, 

 and by Dr. Coulter in Lord Roden's demesne, Dundalk. Mr. Hincks 

 has lately procured it near Cork. As the C. lacustris is local in En- 



\ Mr. Gray's observation on the local distribution of Cyclas rivicola 

 (Man. p. 34.) induces me to mention that I have obtained it in the canals 

 about Leamington, Warwickshire. I have not seen any specimens that could 

 properly be authenticated as Irish. 



