116 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 54. 



SYSTEMATIC DESCRIPTIONS. 



The following description of the new species of brachiopod is con- 

 tributed by Prof. Charles Schuchert, of Yale University: 



DISCINISCA SINGEWALDI, new species. 



This common and very interesting inarticulate brachiopod is 

 related to the lamcllose and nonradially striate Discinisca lameUosa 

 (Brodcrip)' which lives in less than 60 feet of water all along the 

 South American coast from Chile to Panama. The new species is 

 small for the genus and differs from all other forms in that there is 

 a more or less distinct and flat false area beneath the elevated beak 

 or umbo of the dorsal valve. The outline of the shells varies fi'om 

 circular to oval; the dorsal valve is moderately convex with the 

 umbo marginal or nearly so, and the abundant lamellae all terminate 

 in decidedly projecting bands; the ventral valve is more or less 

 flat, less distinctly lamellose, and the pedicle cleft is open from the 

 umbo, which is situated at about one-third the length of the shell, 

 to the posterior margin. 



A nearly circular shell measures 10 mm. long, 11 mm. wide, and 

 4 mm. high. An oval specimen measures 9 mm. long, 7 mm. wide, 

 and 2.5 mm. high. 



Locality and geologic age. — These shells were collected by Profes- 

 sors Singcwald and Miller at Huakachi Hill, near Potosi, Bolivia, at 

 an elevation of 13,500 feet above the level of the Pacific Ocean. In 

 regard to the age of the strata yielding these brachiopods, it can be 



I See Davidson, Trans. Linnean Soc. London, Zoology, vol. 4, 1888, pp. 197-200; and Blochmann, Unter- 

 suchungen iiber den Bau der Brachiopoden, Jena, 1900, pp. 69-70. 



