MR. S. P. 1IARMEK ON THE OCCURRENCE OF THE “ WELL-SHRIMP.” 489 
XIII. 
OX THE OCCURRENCE OF THE “WELL-SHRIMP,” 
NIPHARGUS, NEAR NORWICH. 
1>y Sidney F. Harmer, Sc. I)., F.R.S. 
Read 28th March , 1899. 
In January, 1899, I received two living specimens of Ni/ihartjus, 
liom a well at my father’s house at Cringleford, near Norwich. 
The well, which is about twenty-live years old, is forty feet deep, 
including some three or four feet of water. It is sunk in the chalk, 
which at that spot comes within two or three feet of the surface and 
is overlaid by humus only. As I have been unable to find any 
previous notice of this genus as an inhabitant of East Anglia, its 
occurrence at Cringleford may be worth putting on record. The 
British localities given by Spence Bate and Westwood* are all 
from the Southern Counties, with the exception of Worcestershire 
and Dublin, although the genus has heen recorded from many 
localities on tho Continent of Europe. 
Niphanjus is a small A mphipod Crustacean, and is interesting 
as being a typical member of the cavernicolous fauna, with 
rudimentary eyes. It can readily be distinguished from Gamvuirus 
pulex , the common “Freshwater Shrimp,’ by its colourless, semi- 
transparent appearance, and by the slenderness of its form. 
Three species of this genus are recognised as British by Spence 
Late and Westwood ; and are distinguished from one another 
principally by the form of the “hands” of the “gnathopods” 
(the appendages ot the first and second free thoracic segments), 
and by the shape of the abdominal segments. The form of the 
hands ot the Cringleford specimens .at once excludes A", hnchianus , 
leaving the choice between N. aqnilex, Schiodte and N. fontanus, 
Spence Bate. Although I have had a little difficulty in deciding 
* ‘ History of the British Sessile-eyed Crustacea,’ vol. i. 1803, pp. 311-325. 
