ART. 4 CAMBIAN CONCHOSTRACA — ULRICH AND BASSLER 125 



Pago 

 Figures 12, 13. Dielymella brevis, new species 89 



Two examples of the large, relatively short carapace of 

 this species, natural size. 



Lower Cambrian quartzite: Sunset Hill, near Lake Dun- 

 more, Salisbury, Vt. 

 14-16. "Leperditia tatei" Chapman 102 



A right valve, X 2 (14), left valve, X 5 (15), and a nar- 

 rower specimen, X 2.5 (16). 



Upper Cambrian limestone: Curramulka, Australia. 



17. Leperditia capsella Chapman 101 



Left valve, X 5. 



Upper Cambrian limestone: Curramulka, Australia. 



18. "Isochilin asweeti" Chapman 102 



Right valve, X 2.5. 

 ^ Upper Cambrian limestone: Curramulka, Australia 



(14-18 are after Chapman, 1918.) 



