422 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



DESCRIPTION OF PLATE 50 



PAGE 



Bathyuriscus belcsis Walcott 338 



Fig. I. (Natural size.) Cranidium compressed in shale. U. S. Na- 

 tional Museum, Catalogue No. 62667.. 



la. (Natural size.) Associated free cheek. U. S. National Mu- 

 seum, Catalogue No. 62668. 



lb. (X4-) Small cranidium. U. S. National Museum, Catalogue 

 No. 62669. 



ic, ic'. (X2.) Dorsal view and profile of a small pygidium. 

 U. S. National Museum, Catalogue No. 62670. 



id. (X2.) A more elongate pygidium than that represented by 

 fig. IC. U. S. National Museum, Catalogue No. 62671. 



le, le'. (X6.) A small associated pygidium (and side outline) 

 that has well-defined furrows on the pleural lobes. U. S. 

 National Museum, Catalogue No. 62672. 



if. (X2.) Hypostoma. U. S. National Museum, Catalogue No. 

 62673. 



ig. (X2.) Posterior portion of an hypostoma. U. S. National 

 Museum, Catalogue No. 62674. 



ih, If. (X2.) Portions of thoracic segments. U. S. National 

 Museum, Catalogue Nos. 62675, 62676. 



All of the specimens illustrated by figs, i, la-i, are flattened in a 

 fine Lower ? Cambrian argillaceo-arenaceous shale that occurs at 

 locality 4V, Gordon Creek, Powell County, Montana. 



Bathyuriscus belus Walcott 339 



Fig. 2. (X 2.) Cranidium that has lost much of its convexity by being 

 crushed in the shale. U. S. National Museum, Catalogue 

 No. 62677. 

 20. (X2.) A cranidium preserving the postero-lateral limbs. U.S. 



National Museum, Catalogue No. 62678. 

 2b. (X4.) A small associated pygidium. U. S. National Museum, 



Catalogue No. 62679. 

 2c. (Natural size.) Matrix of a large pygidium. U. S. National 



Museum, Catalogue No. 62680. 

 2d. (X4-) Associated hypostoma on rock with specimen repre- 

 sented by fig. 2b. U. S. National Museum, Catalogue No. 

 62681. 

 The specimens represented by figs. 2, 2a-d, are more or less flat- 

 tened in a fine arenaceo-argillaceous shale at locality 4w, Lower ? 

 Cambrian : Youngs Creek, Powell County, Montana. 



Dolichomctopus suecicus Angelin 372 



Figs. 3, 3'. (Natural size.) Dorsal and side views of a cranidium re- 

 taining a portion of the outer test. U. S. National Mu- 

 seum, Catalogue No. 62682. 



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