334 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii. 



OBOLUS (LINGULEPIS) ROWEI, new species. 



In outline and convexity the valves of this species are closely related 

 to those of 0. {Luigulepis) acuminatum. It differs from the latter 

 and other described species b}^ the strong, raised, concentric lines, 

 Avith very imperfectly defined fine striae between them. 



The specific name is given in memory of Mr. R. B. Rowe, assistant 

 geologist, who collected the material representing this species a short 

 time before his death. 



Formiition and locality. — Middle Cambrian. Reddish-brown sand- 

 stone. Resting Springs, Inyo Countj^, California. 



OBOLUS (WESTONIA) ALANDENSIS, new species. 



Lingida.'' !^p. No. 2. LhiguleUa ? sp. Nos. 3 and 5. Wiman, Bull. Geol. Institute, 

 Upsula, No. 2, VI, 1903, Pt. 1; Studien Nordbaltische Silurgebiet, p. 52, 

 pi. II, figs. 33, 35, 39. 



This species is characterized by its l)road form when compared with 

 O. { Weston m) hottiiica^ O. (Westonia) wimani, and O. ( Weston ia) hal- 

 tica. Its surface is marked by fine concentric lines of growth, with 

 very fine, thread-like, concentric strijB between them. Under a strong, 

 reflected light, almost microscopic, transverse, very irregular lines 

 can be seen that give the surface somewhat the appearance of that of 

 O. ( Westonia) ell a. 



Formation and locality. — Middled Cambrian. Gray, bituminous 

 sandstone in drift bowlders on Aland and Biludden shores of Gefle 

 Bay, Sweden. 



For reference to geological horizon, see description of O. ( Westonia) 

 hottnJra. 



OBOLUS (WESTONIA) BALTICA, new species. 



LiiiguleUa f sp. No. 4 and 6. Wiman, Bull. Geol. Institute, Upsala, No. 2, VI, 

 1903, Pt. 1; Studien Nordbaltische Silurgebiet, p. 52, pi. ii, figs. 34, 37, 38. 



This species is characterized by its elongate form, with the sides of 

 the dorsal valves regularly rounded from the back to the rounded 

 frontal margin. The dorsal valves are also more regularly and 

 strongly convex than in other species occurring in the Cambrian 

 sandstones of Sweden. The outer surface is marked by concentric 

 and radiating stria?, crossed obliquely by very fine, irregular trans- 

 verse striffi. The latter are only to be seen with a strong magnifier 

 and favorable light. 



Formation and locality. — Middled Cambrian. Gray, bituminous 

 sandstone. Drift bowlders at Biludden, shore of Gefle Bay, and 

 Skalstenarne. Also near Of verb}' in the "Gemeinde of Jomala 

 Aland.'' 



