EXPLANATION OF PLATE XLVI. 



Criockras plectoidks, Kth.fil. 



Fig. 1. Lateral view of a partially testiferous example, with a row of 

 obtuse, node-like tubercles along the abdominal angle :it variable 

 distances apart — from three to ten intermediate and nontuberculate 

 costte (see Plate xlvii., figs. 1-4) ; sutures are visible. 



CraocERAs, sp. 



,, 2. Lateral view of a partly testiferous shaft or limb, the proximal end 

 not concealed, but simply hooked as in D'Orbigny's Hamites. The 

 primary costa: only bear tubercles in two rows, one abdominal, the 

 other lateral (see Plate xxxv., fig. 2; PI. xlii. , fig 1 ; PI. xlvii., 

 fig. 5, which may be identical). Seven-ninths the natural size. 



