220 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



DESCRIPTION OF PLATE 30 



PAGE 



Bidentia diMcUis Walcott 174 



Fig. I. (X2.) Side view of a flattened specimen that has been injured 

 by water percolating through the shale. The antennae (a') 

 are fairly well shown. U. S. National Museum, Catalogue 

 No. 57701. 



Emeraldella brocki Walcott 203 



Fig. 2. (X2.) A specimen flattened out so as to give a partial view 

 of the head and body and a fine profile view of the abdomen 

 and telson. e = eye, a' = antenna, mx' = maxillula, mx" = 

 maxilla, thl = thoracic legs, i = alimentary canal. U. S. 

 National Museum, Catalogue No. 57702. 



Burgessia bella Walcott (see pi. 27) 177 



Fig. 3. (X3.) Profile view of a specimen with carapace crushed and 

 distorted. U. S. National Museum, Catalogue No. 57679. 

 4- (X3-) Side view of another specimen in which the carapace 

 has been crowded off the body and out of shape. U. S. 

 National Museum, Catalogue No. 57680. 



The specimens illustrated on Plate 30 are from locality (35k) Middle 

 Cambrian : Burgess shale member of the Stephen formation, on the west slope 

 of the ridge between Mount Field and Wapta Peak, one mile (1.6 km.) 

 northeast of Burgess Pass, above Field, British Columbia. 



i 



