NO. 6 MIDDLE CAMBRIAN BRANCHIOPODA, ETC. 185 



to the genus. All that is known of its appendages is shown by figure 

 4. A number of specimens of the valves in the collection average 5 

 to 8 mm. in length. 



Formation and locality. — Middle Cambrian: (35k) 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. 



HYMENOCARIS OBLIQUA, new species 



Plate 32, figs. 1-3 

 This form differs in the form of the carapace from H. perfecta, as 

 may be seen by comparing figures 1-3, plate 32, with figure i, plate 



31- 



Formation and locality. — Middle Cambrian: (35k) 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. 



HYMENOCARIS OVALIS, new species 



Plate ^2, figs. 5 and 6 



The outline of a valve of the carapace is illustrated by figure 5> 

 which is 15 mm. in length. A laterally compressed carapace and abdo- 

 men are represented by figure 6. These two figures illustrate all that 

 is known of the species. 



Formation amd locality. — Middle Cambrian: (35k) 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. 



HYMENOCARIS ? PARVA, new species 



Plate 32, fig. 7 



This small species is represented by two specimens. At first it 

 was placed with H. ? circularis (pi. 32, fig. 4), but later it was found 

 to differ in its appendages. The specimen illustrated by figure 7 has 

 the carapace crushed down so as to appear broad oval in outline, but 

 another specimen has a nearly straight dorsal margin. The abdomen 

 is pushed over on to the carapace. The antennae project from the left 

 side. 



Formation and locality. — Middle Cambrian: (35k) 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. 



