FAMILY COLIMACEA. 105 



Shell ; sinistral, minutely umbilicated, conically turreted, of seven 

 whorls, transparent horny, finely striated, aperture rather 

 small, lip thin, thinly reflected. 



We have in Britain, plentifully diffused from North Scotland to 

 the Channel Islands, plentifully diffused also throughout Europe 

 from Sweden to the islands of the Mediterranean and Atlantic, a 

 little moss-buried snail, carrying a horny sinistrally convoluted tur- 

 reted shell of only seven whorls, which belongs neither to Bulimus, 

 Clausilia, nor Pupa. It is not like the shell of Bulimus, for it is 

 of very delicate transparent horny substance coiled sinistrally ; it is 

 not lite that of Clausilia, which is of a different texture, more cylin- 

 drically acuminated, and has the special provision of a clausilium, 

 with teeth and winding plates in the mature aperture, which 

 Balea has not ; it is not like Pupa, which, including Vertigo, is of 

 a peculiar shortly cylindrical form, mostly furnished in the mature 

 aperture with teeth. 



In attempting to monograph this genus, Dr. Pfeiffer has included 

 species, such as the large Brazilian Pupa elatior of Spix, which 

 have no relation whatever with it, and has abandoned them ; and 

 in a subsequent edition of his monograph, he included two Sand- 

 wich Island snails described by Dr. Newcomb as Balea, which he 

 has had to abandon. In the third and latest edition of Pfeiffer's 

 monograph of Balea, a Cuba shell described by G-undlach (B. 

 Funcki), and a shell described by myself thirteen years ago, from 

 the Andes of Caxamarca, Peru (Bulimus Clausilioides) , were in- 

 cluded, but neither of these can be regarded as representatives in 

 the Western Hemisphere of the European Balea. It is more than 

 probable that the genus will have to be restricted to the European 

 species, which, in addition to B. perversa, distributed throughout, 

 include B. Sarsi, described as inhabiting Norway and Sweden, and 

 B. Tristensis and ventricosa inhabiting the island of Tristan 

 dAcunha. Even these may prove to be varieties. 



The animal of Balea scarcely differs from that of the genera 

 already cited. 



1. perversa. Shell small, turreted, transparent horny, of six to 

 seven finely striated whorls convoluted sinistrally, with a 

 simple small aperture having a thinly reflected lip. 



