NO. 1395. CAMBRIAN BRA CBIOPODA— WALCOTT. 311 



KUTORGINA SARDINIAENSIS, new species. 



Kuiorgina cingulataBoMNEMANy:, Nova Acta der Ksl. Leop-Carol. DeutHch. Acad. 



Naturf., LVI, 1891, No. 3, p. 440, pi. xix, figs. 22, 23. 

 Lhigula rouaulti Bornemann, Nova Acta der Ksl. Leop-Carol. Deutsch. Acad. 



Naturf., LVI, 1891, No. 3, p. 439, pi. xix, fig. 21. 



Transversely oval, more or less arched, with straight margin which 

 is a little shorter than the greatest breadth of the shell. Surface shows 

 strong concentric lines of growth. 



Found quite connnonly in the slates with OJenopsis and Metado.r- 

 iileii near Canalgrande, solitary also in sandstone with Archmocyatltus 

 on Punta Pintau. The specimens in slate are always pressed very 

 fiat, and are imperfect; in the sandstone are found impressions of the 

 outer surface. 



Here belongs perhaps also the shell designated above as Linguhi 

 rouaulti (?). 



The specimens of this species are all more or less flattened in the 

 argillaceous shale. It appears to be congeneric with Kutorcjhiu cin- 

 guhita^ but not specifically identical with it. 



For mat wn and locality. — Middle? Cambrian shales near Canal- 

 grande, and in sandstone on Punta Pintau, Island of Sardinia. 



KUTORGINA, species undetermined. 



Ventral valve transverse, moderately convex; length 6 mm., width 

 8 mm. ; pseudo area short and sloping beneath the apex at an angle of 

 about 45^. 



A single cast from a coarse sandstone is all that is known of this 

 species. It may be a young shell of K. cinguJata., but the means of 

 comparison do not justify such a reference. 



Formation and locality. — Lower Cambrian sandstone of Soilings 

 Mountain, 2 miles east of Natural Bridge, Virginia. 



RUSTELLA, new genus 



All that is known of this genus is the type species, Rustella cdxoni. 

 It appears to l)e the most primitive form of brachiopod known. 



The generic name is given in memory of William P. Kust, of Tren- 

 ton Falls, New York, whose collections from the Lower Cambrian 

 strata of Georgia, Vermont, were most extensive and the material the 

 finest obtained there. 



RUSTELLA EDSONI, new species. 



General form, subcircular, biconvex. Ventral valve moderatel}' 

 convex, with the apex at the posterior margin immediately al)ove a 

 low arch in the posterior margin. Surface smooth except for concen- 

 tric growth lines and low ridges that in some shells are quite prominent. 

 A shallow, broad, rudimentary pedicle groove occurs beneath the apex 



