6 SMITHSONIAN MISCKLLANEOUS COI-LECTIONS VOL. 97 



localily belongs to the Wilbenis formation, the horizon of the sand- 

 stone is in question. 



L. longula is associated with Obolits sinoc, from which its elongate 

 shape readily distinguishes it. Compared to L. perattenuata, L. 

 longula averages much smaller in size and is more slender. Onh- 

 dorsal valves are figured by Walcott but ventral valves are present 

 in the collection. The shell has the usual growth lines well marked. 

 The smaller type specimen is about 5 mm long and 3 mm wide. 



Upper Cambrian, Hickory; (loc. 68y) Packsaddle Mountain, 11 

 miles southeast of Llano, Texas. 



Cotypcs. — U.S.N.M. no. 27422. 



Lingulella hilli, n. sp. 



Obohts (Lingulella) acutangnhis Walcott, Proc. U. S. Nat. Mus., vol. 21, 



p. 392, pi. 27, fig. 6; pi. 28, figs. I, 2, 1898. 

 Liin/iilclla acitlangula Walcott (part), U. S. Geol. Surv. Men. 51, p. 474, 



pi. 17, figs. I a, b, c, f, h, j, 1 91 2. 

 Lingulella arguta Bridge, U. S. Geol. Surv. Prof. Paper 186-M, p. -'45, 1937. 



Bridge recently pointed out that Walcott's L. acutangnla is not 

 related to Lingulepis acutangnla of Roemer with which it was identi- 

 fied, and further suggested that this brachiopod is L. arguta. How- 

 ever, Bridge failed to note that several species from dift'erent hori- 

 zons were included by Walcott in L. arguta. 



Walcott's original identification of Roemer's species was based on 

 the Hickory sandstone specimens described here as L. Jiilli. Sub- 

 sequently (1912) Walcott added Wilberns specimens which belong 

 to a much larger species. The matrix of L. hilli is a black rock, 

 consisting mainly of hematite in which there are scattered poorly 

 rounded grains of clear quartz. The brachiopods are not compressed 

 and many specimens retain a limy shell. This material was collected 

 by R. T. Hill about 1885 from an undetermined locality in Llano 

 County. When the shell is dissolved, many specimens show the inter- 

 nal features, which explains W^alcott's choice of them to illustrate the 

 species even though the locality is unknown. 



L. hilli varies in size, averaging about 7 mm long and 4.5 mm 

 wide for the ventral valve, with the dorsal relatively shorter. The 

 other features are those usually characterizing Lingulella species. 



L. hilli is larger and wider than L. arguta from Nevada. 



Upper Cambrian, Hickory ; Llano County, Texas. 



Cotypcs. — U.S.N.M. no. 35240. 



