Mr. J. E. Gray on the Clausium of Clausilia. 243 



XXVII. — Some Remarks on the foregoing Paper of Dr. L, 

 Pfeiffer, especially on the Clausium of Clausilia. By John 

 Edward Gray, F.R.S. Keeper of the Zoological Collec- 

 tion in the British Museum. 



To the Editors of the Annals of Natural History. 



Dear Sirs, — I have read Dr. L. PfeifFer's paper with great 

 interest, though, as you will perceive by the following re- 

 marks, I differ from him in some particulars, as I consider 

 he has just been doing what he blames others for, that is, at- 

 tempting to establish a genus which when examined by his 

 own views will not stand. The genus which he describes has 

 been long known to English conchologists under the desig- 

 nation of Brachypus, of the late Rev. Lansdown Guilding, 

 but finding this name preoccupied, he afterwards changed it 

 to Siphonostoma. It will be found characterized under the 

 latter name in Mr. Swainson's volume of Lardner^s Cyclopae- 

 dia, p. 168, f. 22, and 333, f. 97, d and e, where the Clausilia 

 collaris of luom.,— Turbo truncatulus, Wood's Cat. Supp. f. 27, 

 a species first figured by Lister, is called Siphonostoma cos- 

 tata^. I have long separated the group in my cabinet ; but 

 Dr. L. Pfeiffer appears to have overlooked one of the most 

 essential characters of the genus, namely that there is always 

 a slight groove in front of the mouth of the shell, forming a 

 ridge or keel on the front of the last whorl, as in Clausilia. 

 This groove appears to have given rise to Guilding^s latter 

 name of the genus. 



I do not consider this natural and geographical group, 

 which is only established on conchological characters, as more 

 distinct in the family of HeUcidae, than all those genera which 

 Dr. L. Pfeifier in this paper proposes to get rid of, as for ex- 

 ample Anastoma, Achatina, Pupa, Balcea, Partula, Megaspira, 

 and Achatinella, which are all equally natural and groups of 

 confined geographical distribution. If such groups are to be 

 used as genera all the above-named must be retained, and 

 many more established, and at the same time I consider they 

 are all much more distinct from each other than Vertigo is 



* costafum. 

 S 2 



