490 MR. S. F. HARMER ON THE OCCURRENCE OF THE u WELL-SHRIMP.” 
between these two species, it appears to me that the animal is to be 
referred to N. aquilex*, with which it agrees in the relatively 
small size of the hands and in their shape, as well as in the 
rounded form of the lateral parts of the abdominal segments. The 
length of the head and body of the larger specimen, not including 
the appendages, is one-fifth of an inch. 
The genus Niphargus was established by Schiodte, in a paper 
on the Subterranean Faunat ; a species, N. stygius, being described 
from the Adelsberg Caves. In 1855 Schiodte described as 
a second species, iV. aquilex X, the form which had been obtained 
from wells at Maidenhead, and at first supposed to be referable 
to N. stygius. 
Spence Bate in 1859 § described two new species, N. fontanus 
and N. kochianus, from specimens taken from wells at Ringwood 
in Hampshire, in company with another new subterranean 
Amphipod, Crangonyx subterraneus ; N. fontanus feeing at the 
same time recorded from wells at Corsham in Wiltshire. Hogan, 
in the same volume ||, gives an account of the habits of the living 
N. fontanus, mentioning his suspicion that these animals some- 
times devour one another. This is confirmed by the fact that 
although two living specimens were received by me in a small 
tube, the smaller one was shortly afterwards found in a fragmentary 
condition under circumstances which indicated that it could only 
have been the larger individual which had attacked it. 
The occurrence of these subterranean Crustacea in wells ■which 
are not apparently connected with other masses of fresh water has 
always excited much interest, and the literature of the subject has 
become very voluminous. In addition to the works which have 
* N. aquilex should perhaps be more properly considered a synonym of 
N. puteawus, Koch. See, on this point, Wrzesniowski (quoted on p.491) p. 662. 
f“ Bidrag til den underjordiske Fauna,” c Kgl. danske Vid. Selskabs 
Skrifter ’ (Copenhagen), Naturh. og Math. Afdeliug, 5 ser. vol. ii. 1851, p. 26. 
X“ Om den i England opdagode Art af Hulekrebs-Slaegten Niphargus,” 
‘Oversigt over det Kgl. danske Vid. Selskabs Forhandl. i Aaret 1855’ 
(Copenhagen), p. 350. An abstract of this paper and the preceding one, 
with figures, appears in ‘ The Natural History Review,’ vol. iv., 1857, 
“ Notices of Serials,” p. 4*1. 
§ Proc. Dublin Univ. Zool. and Rot. Assoc, vol. i. 1859, p. 237. 
II P* 241. 
