NO. 3 BURGESS SHALE FOSSILS WALCOTT 29 



Labruni. — The labrum is attached to the strong frontal rim 

 (doublure) of the ventral side of the carapace (fig. 9), and extends 

 back to within a short distance below the posterior median margin of 

 the carapace ; its posterior lateral angles are extended into short, spine- 

 like projections and the posterior margin appears to have been pro- 

 vided with two short points. The labrum appears to have covered the 



Fig. 9. — MarrcUa splcndcns Walcott. 



Restoration as described in text: o, antennae; c.sp., carapace spine; d, doub- 

 lure or reflex of anterior margin of carapace; c, eye; en, endopodite ; c.v, 

 exopodite ; m, mandible; m' , maxillula ; ;;;", maxilla; /, telson. 



anterior portion of the mouth ; this is indicated by the proximal end of 

 the protopodite or basal joint of the large mandible and that of the 

 antennae passing beneath it in many specimens (see pi. 22). 



Eyes. — The eyes (fig. 9) have not been seen from the dorsal side 

 of any of the several hundred specimens preserving the carapace, and 

 rarely from the ventral side; this leads to the conclusions (a) that 

 they were located on the lower anterior margin in such a position 

 as to be concealed when the carapace was flattened by compression ; 



