690 CAMBRIAN BRACHIOPODA. 



ACROTBETA IDAHOENSIS STJLCATA Walcott. 



Plate LXV, figure 5. 



Acrotreta idahoensis sulcata Walcott, 1902, Proc. U. S. Nat. Mus., vol. 25, p. 588. (Characterized as below as a new 

 variety.) 



This sti'ongly marked ventral valve is associated with the variety alta, but in its rounded 

 posterior side and strong median groove it is quite distinct. The apex is broken off so as to 

 show the cast of a small apical callosity and the base of a minute foraminal tube. 



This form owes its varietal name to the fact that it possesses a sulcate ventral valve. 



FoEMATioN AND LOCALITY. — ^Tipper Cambrian: (30h) About 350 feet (106.7 m.) above the Middle Cambrian and 

 2,950 (899.2 m.) below the top of the Upper Cambrian, near the base of the arenaceous limestones forming 2a of the 

 Orr formation [Walcott, 1908f, p. 177], on Orr Bidge, about 5 miles (8 km.) south of Marjum Pass, House Range [Wal- 

 cott, 1908f, PI. XIII], Millard County, Utah. 



(54t) Limestone of the St. Charles formation [Walcott, 1908a, p. 6], about 250 feet (76 m.) above the Middle Cam- 

 brian, on the north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida County, 

 Idaho. 



Middle Cambrian: (S4s) Dark blue-gray Langston limestone [Walcott, 1908f, p. 198], just above the Cambrian 

 quartzitic sandstones, north side of Twomile Canyon, near its mouth, 2 miles (3.2 km.) southeast of Malade, Oneida 

 County; (55c) Spence shale member of the Ute limestone [Walcott, 1908a, p. 8], about 50 feet (15.2 m.) above the Brigham 

 quartzite and 2,755 feet (839.7 m.) below the Upper Cambrian, in a ravine running up into Danish Flat from Mill 

 Canyon, about 6 miles (9.6 km.) west-southwest of Liberty and 15 miles (24.2 km.) west of Montpelier, Bear Lake 

 County; and (322a) Langston limestone near Paris, Bear Lake County; all in Idaho. 



Acrotreta inchoans (Barrande). 



Plate XV, figures 7, 7a. 



Lingula inchoans Barrande, 1868, Faune silurienne des environs de Hof, en Baviere, p. 102, figs. 74 and 75. (De- 

 scribed in French as a new species ; see below for translation. Figs. 74 and 75 are reproduced in this mono- 

 graph, PI. XV, figs. 7 and 7a, respectively.) 



Lingula inchoans Barrande, 1868, Neues Jahrb. fur Mineralogie for 1868, p. 692, unnumbered plate, figs. 74 and 75. 

 (Copy of preceding reference.) 



Acrothele inchoans (Barrande), Pompeckj, 1896, Tremadoc Fossilien bei Hof, p. 3. (Discussed in German,) 



Acrolhele inchoans (Barrande), Matthew, 1902, Bull. Nat. Hist. Soc. New Brunswick, vol. 4, pt. 5, No. 20, p. 404. 

 (Mentioned.) 



Acrothele inchoans (Barrande), Matthew, 1903, Geol. Survey Canada, Kept. Cambrian Rocks Cape Breton, p. 103. 

 (Copy of preceding reference.) 



The original description by Barrande follows: 



Under this name we unite several very small shells, rounded in appearance, but more or less elongated, which, 

 however, might represent merely the youthful form of another species. These very flat shells show one or two con- 

 centric grooves at the external contour. The one which is represented in figure 74 [PI. XV, fig. 7, of this work] 

 has, moreover, in the middle a faint longitudinal groove which extends nearly throughout its length. 



Dimensions: Length, 2 mm.; breadth, 3.2 mm. on the specimen in figure 74 [Pi. XV, fig. 7, of this work]. 



Observations. — Pompeckj wrote me that he had concluded that this species was an Acrotreta 

 and not a Lingula. The illustrations and descriptions of Barrande suggest that the specimens 

 represent the compjessed dorsal valves of Acrotreta. 



Matthew [1902a, p. 404] places this species under Acrofhele, but with only the figure given 

 by Barrande I prefer to accept Pompeckj 's provisional reference to Acrotreta. 



Formation and locality. — Passage beds between the Upper Cambrian and the Ordovician: (303c [Barrande, 

 1868a, p. 102]) Darh argillaceous shale in the suburbs of Hof ; and (303f [Pompeckj, 1896a, pp. 7 and 8]) railway cut near 

 Schellenberg, a little distance back of the railway station at Neuhof, near Hof; both in Bavaria, Germany. 



1 Acrotreta inflata (Matthew). 



Plate LXXVI, figures 1, la-k, 2, 2a. 



Lingulella? inflata Matthew, 1886, Trans. Roy. Soc. Canada for 1885, 1st ser., vol. 3, sec. 4, No. 4, p. 33, PI. V, figs. 

 7 and 7a. (Discussed as a new species. The specimen represented by figs. 7 and 7a is redrawn in this mono- 

 graph, PI. LXXVI, fig. 2.) 



Lingulella? inflata Matthew, 1895, Trans. New York Acad. Sci. for 1894-95, vol. 14, p. 127, PI. V, figs. 3a-b. (Men- 

 tioned. Figures copied from preceding reference.) 



