112 



BRITISH FRESHWATER RHIZOPODA. 



Dimensions : Length of test 183 /jl; breadth 133 jj,; 

 breadth of mouth 29 ix (G. S. West). 



In wet Sphagnum ; recorded only in Britain by West 

 (' Journal of the Linnean Society,' XXVIII, ZooL, p. 

 323) from below the outlet of Llyn Idwal, North Wales. 



Leidy considers this species related to N. carinata. 

 It is rare in America as well as in Europe. That 



i'lG. 94. — Nehela equicalceus. After Leidy Joe. cit. (reduced to three- 

 fifths), a and b, broad and narrow views of an active individual; 

 c, broad view of the same with the saroode retracted; d, view 

 from above as seen in the normal position, x 150. 



author describes the horse-shoe-shaped keel as extend- 

 ing below the crown for about two-thirds the length 

 of the test. The structure of the test, independently 

 of the keel, is the same as in N. collaris. 



[After giving the name equicalceus to this species, 

 Leidy changed it to hippocrepis, but the author of a 

 specific name which he has once published can onlv 

 change it (further than correcting a mis-spelling) if it 

 is found to be pre-occupied.] 



