76 BULLETIN 53, UNITED STATES NATIONAL MUSEUM. 



4094. Plastomenus trionychoides (Cope). Type. 



Cope, Sixth Ann. Rept. U. S. Geol. Surv. Terr, for 1872, 1873, P- 

 619; Rept. U. S. Geol. Surv. Terr., Ill, 1884, p. 123, pi. 18, fig. i. 



See Anosteira trionychoides. 



4971. Pleurocoelus altus Marsh. Type. 



Tibia, proximal and distal ends of fibula. Potomac (Juras- 

 sic). Prince George County, Maryland. 

 Marsh, Amer. Journ. Sci. (3), XXXV, 1888, p. 92. 

 = Astrodon altus. 



4968. Pleurocoelus nanus Marsh. Cotypes. 



4969. Dorsal, sacral, and caudal vertebrae. Potomac (Jurassic). 



4970. Prince George County, Maryland. 



Marsh, Amer. Journ. Sci. (3), XXXV, 1888, p. 90, text figs. 1-6; 

 Sixteenth Ann. Rept. U. S. Geol. Surv., 1896, pi. 40, figs. 4-9. 



= Astrodon nanus. 



2267. Pleuroccelus nanus Marsh. Plesiotypes. 



5372. (i) Metacarpal, metatarsal, and ungual phalanx; (2) distal 



caudal vertebra. Potomac (Jurassic). Prince George 

 County, Maryland. 



Marsh, Sixteenth Ann. Rept. U. S. Geol. Surv. for 1894-5, 1896, (i) 

 pi. 41, figs. 1-7; (2) pi. 40. figs. 10, II. 



= Astrodon nanus. 



218. Poicilopleuron valens Leidy. Type. 



Half of vertebral centrum. Cretaceous ? Middle Park, 

 Colorado. 



Leidy, Proc. Acad. Nat. Sci. Phila., 1870, p. 3 (as Poicilopleuron 

 (Antrodemus) valens); Rept. U. S. Geol. Surv. Terr., I, 1873, 

 p. 267, pi. 15, figs. 16-18 (on plate as Antrodemus). 



= Antrodemus valens. 



2135. Priconodon crassus Marsh. Type. 



Tooth. Potomac (Jurassic). Muirkirk, Prince George 

 County, Maryland. 



Marsh, Amer. Journ. vSci. (3), XXXV, 1S88, p. 93, text figs. 7-9; 

 Sixteenth Ann. Rept. U. S. Geol. Surv. 1896, p. 187, pi. 44, 

 figs. 2a-c. 



4126. Protagras lacustris Cope. Type. 



Vertebrae. Bridger (Eocene). Cottonwood Creek, Wyo- 

 ming. 



Cope, Pal. Bull. No. 3, 1872, p. 3; Proc. Amer. Phil. Soc, XII, 

 1872, p. 471; Rept. U. S. Geol. Surv. Terr., Ill, 1884, p. 103, 

 pi. 23, figs. 17, 18. 



4047. Pterosphenus schucherti I,ucas. Type. 



Vertebrae. Jacksonian (Eocene). Cocoa, Alabama. 

 Lucas, Proc. U. S. Nat. Mus., XXI, 1898, p. 637, pis. 45, 46. 



5373. Rhytidodon rostratus Marsh. Type. 



Posterior portion of skull. Triassic. North Carolina. 

 Marsh, Amer. Journ. Sci. (4), II, 1896, p. 61, text fig. 2. 

 = Phytosaurus rostratus. 



