166 CAMBRIAN BRACHIOPODA. 



3t (=3s, which see). (For stratigraphic position and association, see p. 156.) 



3v. (For stratigraphic position and association, see p. 158.) Middle Cambrian: About 200 feet (61 m.) above the 

 Lower Cambrian in the " Spence shale " [Walcott, 1908f, p. 183] (described in this monograph, p. 158, as 

 Ih of the Howell formation), in Dome Canyon, about 5 miles (8 km.) west of Antelope Springs, House 

 Range [Walcott, 1908f, PI. XIII], Millard County, Utah. 

 (See p. 158 for list of species.) 



3w (same horizon as 30g and llq). (For stratigraphic position and association, see p. 156.) Middle Cambrian 

 About 2,350 feet (716.3 m.) above the Lower Cambrian and 2,050 feet (624.8 m.) below the Upper Cambrian, 

 in the central portion of the thin-bedded limestones forming Ic of the Marjum limestone [Walcott, 1908f, 

 p. 180], in the cliff about 2 miles (3.2 km.) southeast of Marjum Pass, House Range [see Walcott, 1908f, 

 Pis. XIII and XV], Millard County, Utah (C. D. Walcott, 1903). 



Lingulella arguta. I Ptychoparia. 



Acrotreta bellatula. | Neolenus. 



3x (=llx). (For stratigraphic position and association, see p. 156.) Middle Cambrian: About 2,200 feet (670.6 

 m.) above the Lower Cambrian and 2, 200 feet (670.6 m.) below the Upper Cambrian, in the limestones forming 

 Id of the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge 

 eastof Wheeler Amphitheater, House Range [Walcott, 1908f, Pis. XIII and XV],.Millard County, Utah (C. D. 

 Walcott, F. B. Weeks, and L. D. Burlins. 1905). 



Micromitra sculp tills. 



Micromitra (Iphidella) pannula ophirensis 



Obolus mcconnelli pelias. 



Obolus rotundatus. 



Lingulella arguta. 



Acrothele subsidua. 



Acrothele subsidua Isevis. 



Acrotreta attenuata. 



Acrotreta ophirensis. 



Eoorthis remnicha?. 

 *Eoorthis thyone. 

 *Syntrophia? unxia. 

 Agnostus 3 sp. 

 Ptychoparia. 



Neolenus inflatus Walcott. 

 Neolenus intermedins Walcott. 

 Neolenus superbus Walcott. 

 Ogygopsis?. 



3y. (For stratigraphic position and association, see p. 156.) Middle Cambrian: About 2,150 feet (655.3 m.) above 

 the Lower Cambrian and 2,250 (685.8 m.) below the Upper Cambrian, in the shaly limestones forming Id of 

 the Marjum limestone [Walcott, 1908f, p. 180], 2.5 miles (4 km.) east of Antelope Springs, in ridge east of 

 Wheeler Amphitheater, House Range [Walcott, 1908f, Pis. XIII and XV], Millaid County, Utah (CD. Wal- 

 cott, F. B. Weeks, and L. D. Burling, 1905). 



Obolus mcconnelli pelias. Ptychoparia. 



Acrotreta ophirensis. Ogygopsis?. 



Agnostus. 



4 (same horizon as 3s). (For stratigraphic position and association, see p. 156.) Middle Cambrian: Drift pieces 

 believed to have come from the Wheeler formation [Walcott, 1908f, p. 181], collected near Antelope Springs, 

 House Range [Walcott, 1908f, PI. XIII], Millard County, Utah (J. F. Gibbs, 1889). 



*Acrothele subsidua. I Ptychoparia kingi (Meek). 



Agnostus interstrictus White. | Asaphiscus wheeleri (Meek). 



4e (see 4m and 4n). Middle Cambrian: Limestones about 950 feet (289.6 m.) above the unconformable base of the 

 Cambrian, in the divide at head of Jackson Creek (locally known as Sheep Creek), a creek flowing into Jack- 

 son Lake about 0.5 mile (0.8 km. ) south of its northwestern corner, Teton Mountains, Grand Teton quadrangle 

 (U. S. G. S.), Uinta County, Wyo. (C. D. Walcott, 1898). 

 *Obolus tetonensis. I *Acrotreta microscopica tetonensis. 



Lingulella (Lingulepis) acuminata meeki. | Billingsella coloradoensis. 



(Possibly the last named is from a bed different from that containing the other species.) 



4g (50 feet below 4h; see 4h, 4k, and 4p). Middle Cambrian^: About 325 feet (99.1 m.) above the base of the Cam- 

 brian, in the Flathead shales of Peale [1893, p. 21], 1 mile (1.6 km.) north of the junction of East Gallatin 

 and West Gallatin (Gallatin) rivers, 4 miles (6.4 km.) east-northeast of Ijogan, Threeforks quadrangle 

 (U. S. G. S.), Gallatin County, Mont. (C. D. Walcott). 

 Obolus (Westonia) ella. 



4h (50 feet above 4g; see 4g, 4k, and 4p). Middle Cambrian: About 375 feet (114.3 m.) above the base of the Cam- 

 brian, in limestone interbedded in the Flathead shales of Peale [1893, p. 21], 1 mile (1.6 km.) north of the 

 junction of East Gallatin and West Gallatin (Gallatin) rivers, 4 miles (6.4 km.) east-northeast of Logan, 

 Threeforks quadrangle (U. S. G. S.), Gallatin County, Mont. (C. D. Walcott). 



Micromitra pealei. I Lingulella (Lingulepis) acuminata meeki. 



Obolus tetonensis. | Acrotreta pyxidicula. 



