M. A. Humbert on Xiphaigus putcanus, var. Forelii. 243 



gie ' for 1S44, pau^r 12, that Mcnesf/io staiuls between Scalaria 

 and Vehdina. His allocation of other genera constituted by 

 ^Ic'iller arc less happy : e. g. Ainaura^ between Xutica and 

 Marijurita ; and AuinetCf between Mitra and Lottia. It is 

 certainly not the Monoptygma of Lea, which has an obliquely 

 spiral fold on the pillar. Couthouy placed a North-American 

 species {striatula), allied to the ])resent, in Brown's genus 

 Pi/ramisj the type of which is Eulima suhuhifa. Pt/ramis 

 striatula of Couthouy has been referred by Stimpson and 

 Binney to the Menestho albula of Miiller ; but it is very much 

 larger and more cylindrical, and the sculpture is diflcrent. 



0. albula appears to be the sole representative in the Arctic 

 seas of the numerous fi^mily of Pyraraidellidse. 



XX. — Description q/Niphargus puteanus, var. Forelii. 

 By Alois Humbert*. 



The existence of Amphipod Crustaceans living in wells and 

 more or less deprived of visual organs was indicated in 1835 

 at Paris and in Germany. MM. P. Gervais and C. L. Koch, 

 who were the first to discover them, referred them to the 

 genus Gammarus. Some years later, Schiodte, who had 

 discovered a species of the same group in the caverns of 

 Carniola and Istria, perceived that these subterranean crus- 

 taceans deserve to form a distinct genus, to which he gave the 

 name of Xipharfjus, which is now generally adopted. 



A great number of memoirs have since been published upon 

 these animals ; and these have furnished us with much infor- 

 mation as to their organi2;ation and geographical distribution, 

 New species of the genus Xipharjus and even new genera 

 allied to the latter have been discovered, both in the subter- 

 ranean waters of wells and caverns and in the sea. Finally, 

 in 1860 M. F. A. Forel indicated for the first time the existence 

 of blind Gammarida; (Xip/iarr/us) in the depths of the lake of 

 Geneva, and in 1873 he found the same animals in the lake 

 of Xcuchatcl. 



Although we may say that our knowledge of the Crustacea 

 of this group has been greatly extended, we must unfortunately 

 add that the subject still presents many doubtful points, and 



• Tranj<late(l by W. S. Dallas, F.L.S., from nn abstract by the author 

 iu the ' BibliotlieqiK' I'liiviTsi'lk' : Archives ilea .Sciences," lAtli Januarv, 

 1877, pp. 08-70. The ori^nual paper appeared iu the ' Jiulletin do hi 

 Soci«5te Vaudoise des Sciences Natiirelles, tome xiv. (1876), pp. l*78-y9s, 

 pl3. & 7. 



