N0.1299. CAMBRIAN BRACIIIOPODA—WALCOTT. 605 



in the apex curving over nearly to the posterior margin. It has the 

 outline of L. vi'muta^ but not the strong vascular sinuses and small 

 cardinal scars of the pedicle valve of that species. From L. h^oadheadi 

 it A aries in outline and convexity. 



Formation and locality. — Middle Cambrian, in shales and sand- 

 stones above the Knox sandstones, Bull Run, Copper Ridge, 11 miles 

 west of Knoxville: 6 miles northeast of Knoxville; 1\ miles east of 

 Post Oak Springs, Roane County, all in Tennessee. 



OBOLUS (LINGULELLA) SCHMALENSEI, new species. 



This is the European representative of the American 01)olus (Z) 

 rotundatus. Its outline is slightly elongate to subcircular. A^'hen 

 the shell is exfoliated the cast indicates that it was strong over the 

 visceral area and thin toward the margins. 



The specific name is given in honor of M. Schmalensee. who col- 

 lected the material for me. 



Formation and locality. — Middle Cambrian limestones of Paradox- 

 ides for chamme^n zone, Skane. Andrarum. Sweden. 



BROGGERIA, new subgenus. 

 Type, Oholus {Broygeria) mlieri. 

 This subgenus difi'ers from the tj^pical forms of Ohoh/s in having a 

 very deep visceral depression in both valves and a minutelv papillose 

 interior surface. A series of shells showing the effect of compression 

 on the appearance of the interior casts of the valves will be illustrated 

 in the monograph. 



OBOLUS (BROGGERIA) SALTERI Holl. 



Obolella sulicri Holl, Quar. Jour. Geol. Soc, XXI, 1S65, p. 101, fig. 9. 



.^ Obolella salteri Davidson, Brit. Fo8,«. Brach., Ill, 1870; Sil. Brach., p. 61, pi. 



IV, figs. 28, 29. 

 Obolus sailer! Brogger, Die Silurisehen Etagen 2 und 3, 1882, p. 44, pi. x, figs. 



10, 11, 13. 

 Obolus ? S-dteri Mickwitz, Mem. Imp. Acad. Sciences, St. Peterslmrg, YIII, 



1896, 4.ser., Xo. 2, p. 19. 



Original description. — Compressed, subtriangular to nearly round, rather broader 

 than long; shell thin; surface grooved concentrically by a few inequidistant, strongly 

 marked lines of growth, and by numerous finer lines which are distinct only on the 

 sides of the shell. Length usually about one-third inch; width slightly more. 



Position. — In the Black Shales. [The Black Shales are referred to Upper Cam- 

 brian, the locality being in the eastern portion of the Malvern Hills of England.] 



Mr. Davidson copies HolFs description and figure. Dr. W. C. 

 Brogger, however, identifies the species from the Upper Cambrian 

 Ceratc/pyge slate and limestone of Sweden, illustrating a form from 

 the slate, and a very beautiful interior of what appears to be a dorsal 

 valve of this species from the limestone. 



