112 BEITISH FRESHWATER RHIZOPODA. 



Dimensions : Length of test 183 /x; breadth 133 ju; 

 breadth of mouth 29 /x (G. 8. 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 Id wal, North Wales. 



Leidy considers this species related to N. carinata. 

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



-fc'ia. 94. Nebela equicalceus. After Leidy loc. cit. (reduced to three- 

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

 c, broad view of the same with the sarcode 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 only 

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

 is found to be pre-occupied.] 



