438 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



DESCRIPTION OF PLATE 58 



PAGE 



Asaphiscus wheeleri .Meek 390 



Fig. I. (Natural size.) This is the largest entire dorsal shield known 



to me. It was found by Mr. G. K. Gilbert of the Wheeler 



Survey. U. S. National Museum, Catalogue No. 62754. 

 la. (X2.) Restoration based upon a nearly entire dorsal shield 



and the specimens represented by figs, lb, ic, \d, if. U. S. 



National Museum, Catalogue No. 62755. 

 lb. (X I-S-) A medium size dorsal shield, somewhat broken by 



compression in the shale. U. S. National Museum, Cata- 

 logue No. 62756. 

 If- (X3-) Small dorsal shield with very perfect thorax and 



pygidium. U. S. National Museum, Catalogue No. 62757. 

 id. (X 2.) Fragment of the anterior half of a cranidium, retaining 



its original convexity. U. S. National Museum, Catalogue 



No. 62758. 

 le. (Natural size.) This is a photograph of one of the type speci- 

 mens illustrated by fig. ic, plate 2 (Geog. and Geol. Explor. 



and Surv. west of looth Merid., 1875, Vol. 4, Pt. i). U. S. 



National Museum, Catalogue No. 15460 [=8576]. 

 if. (X 2.) Interior of a pygidium showing very clearly the anchy- 



losed segments of the axis and pleural lobes. U. S. National 



Museum, Catalogue No. 62759. 

 i&- (X2.) A convex pygidium, showing characters similar to those 



of the pygidium of Dolichometopus productus (pi. 53, fig. 



3). U. S. National Museum, Catalogue No. 62760. 



The specimens illustrated by figs, i, la-g, are from localities 3s and 

 4, Upper Cambrian : Wheeler formation ; east of Antelope Springs, 

 House Range, Utah. 



