I20 SMITHSONIAN MISCUIvLANEOUS COLLliCTlONS VOL. 53 



DESCRIPTION OF PLATE 8 



Page 

 a. = area. /;. = central muscle scar. 



cf. = cardinal muscle scar. i. =transmedian muscle scar. 



F. = foramen. ;. ^anterior lateral muscle scar, 



i^'. = cast of foraniinal tube. t/j. = vascular sinus. 



Obolus (IVestonia) zvasatchensis, new species 69 



Fig. I. Partially exfoliated ventral valve from a drift block sup- 

 posed to have come from a Middle Cambrian horizon 

 1,700 feet (518.2 m.) above the Cambrian quartzitic sand- 

 stones, Wasatch Canyon, 5 miles (8.05 km.) north of 

 Brigham, Box Elder County, Utah. U. S. National Mu- 

 seum Catalogue No. 51733. 

 la. Exterior of a dorsal valve from the Middle Cambrian shales 

 of the Bloomington formation. Blacksmith Fork Canyon, 

 Cache County, Utah. U. S. National Museum Catalogue 

 No. 51734"- 



Dicellomus parvus, new species 76 



Fig. 2. Interior of dorsal valve. U. S. National Museum Catalogue 

 No. 52523". 

 2a. Interior of dorsal valve. U. S. National Museum Catalogue 

 No. 52523^- 



The specimens represented by Figs. 2 and 2a are from 

 Middle Cambrian limestones 2.5 miles (40.2 km.) south- 

 west of Yen-chuang, Sin-t'ai District, Shan-tung, China. 



Dicellomus proliflcus, new species yy 



Fig. 3. Exterior of ventral valve. U. S. National Museum Cata- 

 logue No. 51925a. 

 2a. Exterior of dorsal valve. U. S. National Museum Catalogue 

 No. 5I925&- 



The specimens represented by Figs. 3 and 317 are from 

 Middle Cambrian limestones of the Marjum formation, 

 south of Marjum Pass, House Range, Millard County, 

 Utah. 



Lingulella (Lingulcpis) acuminata scqucns, new variety y2 



Fig. 4. Exterior of type specimen of ventral valve from Ordovician 

 sandstone, near Ticonderoga, Essex County, New York. 

 U. S. National Museum Catalogue No. 53675a. 



Lingulella texana, new species 71 



Fig. 5. Type specimen showing cast of the interior of a dorsal valve 

 from Middle Cambrian limestones on Morgan Creek, Bur- 

 net County, Texas. U. S. National Museum Catalogue 

 No. 51806. 



Lingulella buttsi, new species 70 



Fig. 6. Type specimen showing exterior of a dorsal valve from 

 Upper Cambrian limestones, near Kimbrel, Bibb County, 

 Alabama. U. S. National Museum Catalogue No. 51779. 



