PLATE XLVn. 



ASPIDICIITHYS (?) NOTABILIS (page .''rj-l). 



Figure 1. View of the outer surface of the supposed median veritral 

 plate, from 8outh Manitou Island, Lake Wiuni- 

 pegosis, upon wliich this species is based. One-half 

 the natural size. 



Figure la. A portion of the same, twice the natui'al size, to show the 

 tuberculation of the surface more clearly. 



