a. a ee 
THE ZOOLOGY OF NORFOLK 43 
levisculus in great numbers on brown alga (Palleila) ; Ampelisca spinipes 
is rare in the vicinity of the Point ; Bathyporeia Robertsoniu, a burrowing 
form in the surf-beaten sand ; Haustorius arenarius in similar situations ; 
Corophium volvulator is a mud-burrower forming food for fish and 
waders. 
Isopoda.—-Ligia oceanica crawling over rotten timber ; Idotea linearis 
abound in inshore waters and form food for flocks of immature terns ; 
I. pelagica common under stones and algz on the open beach ; J. granulosa, 
a single specimen, hitherto not previously recorded south of Northumber- 
land ; Eurydice pulchra, a very common pelagic form ; Cyathura carinata, 
first recorded in Britain by Dr. Robert Gurney under stones and behind 
bark of old piles near Acle bridge, was found at Stiffkey burrowing freely 
in the mud ; Spheroma rugicauda in Stiffkey freshes. 
Mysidacea.—Mysids are very common in summer in wreck pools and 
appear to be a favourite food for fish. 
The fresh-water Crustacea have been intensively studied by Dr. R. 
Gurney, and his valuable papers mentioned below not only afford informa- 
tion as to the distribution of the various groups in the Broads, and for the 
county outside that area, but also on the physical features of the Broads, 
and their effect upon the fauna. It is quite impossible even to summarise 
the results of his work, and the writer would refer those interested to 
Trans. N. N. Nat. Soc., vii, 637; ‘The Fresh and Brackish-water 
Crustacea of East Norfolk (1904),’ viii, 410; ‘The Crustacea of the East 
Norfolk Rivers,’ xii, 550; The Fresh-water Crustacea of Norfolk (1928). 
‘The Phytoplankton of some Norfolk Broads,’ by M. B. Griffiths, Jour. 
Linn. Soc. Bot., xlvii, 595, is also a useful paper for consultation with 
reference to the subject. 
One interesting crustacean deserving special mention as apparently 
confined in Britain to our Norfolk rivers, is the new British prawn (Leander 
longirostris), first found by Dr. Gurney, in Breydon, in large numbers ; 
it also occurs in Oulton Broad, in the Waveney, and in the Bure as far up 
as Acle bridge. It is a species which has been found in the Mediterranean, 
in certain estuaries of the west coast of France, and is common in estuarine 
regions in Holland ; the fact that it is confined to Britain in our Norfolk 
rivers leads the discoverer to make the interesting speculation that it is a 
relic of the time when our rivers were tributaries of the Rhine and that the 
larve have the migrating instinct causing them to return to those rivers. 
The distribution of the crayfish (Potamobius Pallipes) in the county has 
not been fully worked out ; it occurs in streams flowing into the Bure, 
in the Yare at Keswick; at Taverham Mill (river Wensum) it is abundant, 
and probably inhabits all the upper waters of the Wensum. 
Myriapopa. 
The systematic collecting of Myriapoda has never been carried on in 
Norfolk ; the species given below were casually picked up by Mr. F. 
Pickard-Cambridge and Mr. O. Thomas on or near the Broads, and by 
the former at West Runton. They are all of wide distribution in the 
southern counties. 
Centipedes.—Lithobius forficatus, L. calcaratus. 
