OBOLID^. 425 



I find in the limestone from Slemmestad a broad form of the ventral valve that closely 

 resembles in outline and surface the shell illustrated by Brogger as "Lingula sp." [Brogger, 

 1882, PI. X, fig. 9], and I think that the specimen represented by figure 12 of the same reference 

 ("Lingula sp.") may also belong to this species. 



Through the courtesy of Doctor Brogger, I studied the material representing this species 

 collected in Norway, including the fine interior of the dorsal valve illustrated on Plate XIII, 

 figure Im, of this monograph. 



In a collection kindly sent me by Dr. G. Lindstrom I find two ventral valves (PI. XV, 

 figs. 4a and 4b) from the black shale of Skane, but it is in the collection made by Mr. Schmalensee 

 that specimens occur showing the casts of the interior of the dorsal valve. These have the 

 imprint of the central visceral area, the large vascular sinuses, and the area (PL XV, fig. 4c). 

 A cast (PI. XIII, fig. lb) of an uncompressed shell proves that the visceral area was short and 

 relatively small. Comparing the latter figure with Plate XIII, figure Im, I am led to conclude 

 that the latter is a partly exfoliated specimen preserving the vascular markings on the thin 

 inner layers of the shell. 



In Cape Breton this species occurs abundantly in association with Lingulella concinna 

 Matthew and Acrotreta hisecta Matthew. The shells are all compressed in the shale, but a 

 direct comparison of the interiors of the valves of specimens from Cape Breton and the Cera- 

 topyge shales of Sweden shows the two to be identical in all characters except the length of the 

 area and pedicle groove. The Cape Breton shells have a longer area, but whether or not this is 

 due to the conditions of preservation I am unable to decide, as the material from Sweden is 

 very imperfect about the area. On one of the Cape Breton shells the fine punctse of the 

 interior surface are clearly shown. 



The specific name was given in honor of Mr. J. W. Salter. 



Formation and locality. — Passage beds between the Upper Cambrian and the Ordovician: (8x) Ceratopyge 

 limestone at Slemmestad, about 3 miles (4.8 km.) southwest of Christiania; (323i [Brogger, 1S82, description of PI. X]) 

 Phyllograptus slate at Krekling, in Sandsvar; (333e [Christiania Univ. Min. Inst.]) Ceratopyge limestone (Etage Saj- 

 of Brogger) at Engervik, in the Christiania region; (323f [Brogger, 1882, pp. 16-17]) lower part of the Ceratopyge lime- 

 stone at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania; and (323h [Brogger, 1882, p. 17]) blue Ceratopyge 

 limestone (a higher horizon than 323f) at Vestfossen, 10 miles (16.1 km.) west-southwest of Christiania; all in Norway. 



(309 [Moberg and Segerberg, 1906, description of PI. 1]) Ceratopyge limestone (zone 4 of Moberg and Segerberg) 

 at Fogelsang, 5 miles (8 km.) east of Lund; and (323j [Brogger, 1882, p. 44]) Ceratopyge limestone at Tosterup; both in 

 the Province of Malmohus, Sweden. 



Upper Cambrian: (304e [Davidson, 1S66, p. 62]) Upper part of the black "White Leaved Oak" shales at Coal Hill, 

 east end of the Malvern Hilh; and (304a [Groom, 1902, p. 110]) "Bronsil" shales in the Malvern Hills; both between 

 Herefordshire and Worcestershire, England. 



(3c[) Shale in Barachois Glen, 4 mOes (6.4 km.) south of Little Bras d'Or Lake; (10c) shale on west side of Bara- 

 chois River; (lOd) shales on west side of Ba.rachois River, 0.125 mile (0.2 km.) north of Boisdale road, opposite McMul- 

 lin's place; (lOm) shales 2 miles (3.2 km.) south of the Boisdale road from Upper Leitches Creek, toward the head 

 of Barachois Pviver; (lOe, lOf, and lOg) shales on the east branch of Barachois River, 0.5 mile (0.8 km.) north of the 

 crossroad from Boisdale to Upper Leitches Creek; (lOi) shale in high bank on west side of Barachois River, just north 

 of the Boisdale road; (101) shale on east bank of Barachois River, 6 miles (9.6 km.) from Little Bras d'Or Lake; (3h) 

 shale and shaly limestone on McNeil Brook, 1.5 miles (2.4 km.) east of Marion Bridge; (lOn) shale in ravine on east side 

 of Barachois Glen, 3 miles (4.8 km.) from Barachois; (13h) shale on east bank of Barachois River, 1.5 miles (2.4 km.) 

 north of Boisdale; and (lOr) arenaceous shales of Division C3a? of Matthew at McAdam Shore, East Bay, east of Bras 

 d'Or Lake; all in eastern Cape Breton, Nova Scotia. 



(323w) Black argillaceous shale of Etage 3a/9 at Christiania, Norway. 



(3901) Limestone band in Ceratopyge slate at Borgholm; (309j) shale at Alunbruk (alum works); (310d) Ceratopyge 

 slate at Borgholm; and (321x) Dictyograptus slate at Alunbruk (alum works); all on Oeland Island, Sweden. 



(390g [Moberg and Segerberg, 1906, p. 64]) « Limestone in the Dictyograptus slate at Sandby, 6 miles (9-6 km.) east- 

 northeast of Lund; (300h) limestones of the Dictyograptus fiahelUformis zone at Fogelsang, 5 miles (8 km.) east of Lund; 

 (323k [Brogger, 1882, p. 44]) Ceratopyge slate at Tosterup; and (309i) limestones at Sandby, 6 miles (9.6 km.) east- 

 northeast of Lund; all in the Province of Malmohus, Sweden. 



Upper? Cambrian: (3091) Shale collected somewhere in Sweden, exact locality unknown; and (310h) shale col- 

 lected somewhere (probably Fogelsang) in the old province of Skane, now the Provinces of Malmohus and Christianstad; 

 both in Sweden. 



a Specimens from this locality are included in the collections of the United States National Museum. 



