400 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



DESCRIPTION OF PLATE 64 



PAGE 



Dikelocephalus ? dalyi Walcott 367 



Figs, i and la. (X 2.) Dorsal and side views of a nearly entire cranid- 

 ium that shows the palpebral lobes to be about midway of 

 its length. Plastotype. U. S. National Museum, Catalogue 

 No. 60061. 



2. (X2.) A fragment of a cranidium with a nearly flat frontal 



limb that is more like the frontal limb of the typical 

 Dikelocephalus than that of fig. i. Plastotype. U. S. 

 National Museum, Catalogue No. 60062. 



3. (X2.) Fragment of the pleural lobe of a thoracic segment. 



Plastotype. U. S. National Museum, Catalogue No. 60063. 



4. 4a. (Natural size.) Dorsal and side views of pygidium illustrat- 



ing the short axial lobe and broad flattened border. Plasto- 

 type. U. S. National Museum, Catalogue No. 60064. 



5. (X 4-) Doublure of posterior portion of pygidium enlarged 



to illustrate imbricating lines. U. S. National Museum, 

 Catalogue No. 60065. 

 The type specimens of this species are at Ottawa in the collection 

 of the Geological Survey of Canada. From Upper Cambrian, 

 British Columbia, Canada. 



Saukia marica (Walcott) 380 



Figs. 6 and 6a. (X 3-) Dorsal and side views of a cranidium which is 

 the type specimen of the species. It was illustrated by fig. 

 13, pi. ID, Monogr. U. S. Geol. Surv., Vol. 8, 1884. From 

 locality 62, Upper Cambrian, Dunderberg shales. Eureka 

 District, Nevada. U. S. National Museum, Catalogue No. 

 24565. 



Calvinella tenuisculpta Walcott 391 



Figs. 7 and ja. (X 2.) Dorsal and side views of a cranidium which is 

 the type specimen of the species. From locality 201a, 

 Lower Ordovician ( ? Ozarkian) : Pogonip limestone. 

 Eureka District, Nevada. U. S. National Museum, Cata- 

 logue No. 60066. 



Conokephalina ornata (Brogger) 387 



Fig. 8. (Natural size.) Dorsal view of a cranidium. (After Brogger, 

 Nyt Mag. for Naturvid.. Vol. 24, 1877, pi. 3, fig. 5- 

 From Middle Cambrian, Krekling, in Sandsvar, Norway. 



