﻿1050 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. \2J 



Plate 27 

 acanthocrania, pachyglossa, petrocrania, schizotreta, trematis 



Page 



A. Schizotreta microthyris Cooper, new species 278 



(1, 2) Apical view of a somewhat exfoliated brachial valve, X 1 and X 2, para- 

 type, 116804a. 



Oranda formation, north side of U. S. Highway 11, 2 miles southwest of 

 Strasburg, Strasburg (15') Quadrangle, Va. 



(3) Imperfectly preserved pedicle interior showing position of foramen, X 2, 

 paratype, 97547c 



Oranda formation, along the railroad \ to \ mile east of Strasburg Junction, 

 Strasburg (15') Quadrangle, Va. 



B. Acanthocrania subquadrata Cooper, new species 286 



(4) Apical view, X 1, of a paratype, 11 6836; (5, 6) apical and side views, X 2, 

 of the same paratype; (7) apical view, X 4, of same. 



Bromide formation (Pooleville member — Lonchodomas zone), Rock Cross- 

 ing of Hickory Creek, about center sec. 35, T. 5 S., R. 1 E., Criner Hills, Carter 

 County, Olda. 



C. Pachyglossa pachydermata Cooper, new species 225 



(8) Brachial view of an exfoliated specimen, the reverse of specimen shown in 

 fig. 17, pi. 5, F, X 1, holotype, 1 16767. 



Botetourt formation, roadside at junction of Virginia Highways 311 and 114, 

 i mile southwest of Catawba, Salem (15') Quadrangle, Va. 



D. Trematis sp. 1 274 



(9) Brachial valve, X 6, figured specimen, 1 17970. 



Whitesburg formation, 2\ miles southeast of Whitesburg, Bulls Gap (T.V.A. 

 171-SE) Quadrangle, Tenn. 



E. Petrocrania dixonensis Cooper, new species 287 



(10, 11) Apical and side views of the brachial valve, X 1. holotype, 45215. 

 Platteville formation, Dixon, Dixon (15') Quadrangle, 111. 



F. Acanthocrania sp. 1 286 



(12, 13) Apical and side views of the brachial valve, X 2, figured specimen, 

 116839; (14) same, X I. 



Lebanon formation (Dolcroides zone), on U .S. Highway 70N, opposite Fair- 

 view Service Station, \ mile west of Rome, Tenn. 



G. Petrocrania trentonensis (Hall) 290 



(15) Pedicle valve of Eoplectodonta alternata with encrusting Petrocrania seen 

 in posterior view, X I, hypotype, 116835; (16, 17) apical and side views, X 2, 

 of the same specimen. 



Martinsburg formation (Salona equivalent), on Virginia County Highway 

 617 = 910, 0.15 mile north of Green Mount Church, Broadway (15') Quad- 

 rangle, Va. 



H. Acanthocrania oklahomensis Cooper, new species 285 



(18) Four individuals encrusting a valve of Opikina, X 1, holotype, 116837a and 

 paratypes, n6837b-d; (19) same, X2; (20) apical view of one of the indi- 

 viduals, X 3, holotype, 116837a. 



Bromide formation (Pooleville member — bed 2), sec. 22, T. 2 S., R. 3 E., west 

 of Nebo, Murray County, Okla. 



Plate 28 

 acrotreta, conotreta, llngulella, pachyglossa, schizotreta, torynelasma 



A. Conotreta triangulata Cooper, new species 254 



(1-4) Respectively tilted, anterior, side, and brachial views of a complete speci- 

 men, X2, holotype, 1 17973. 



