1910.] NATURAL SCIENCES OF PHILADELPHIA. 609 



Cylindrosteus productus Cope. PI. XXXVIII, figs. 10, 11. 



Proc. Acad. Nat. Sci. Phila., 1865, p. 86. San Antonio, Tex. 



Head 2*-3i; depth 3^-34 in head; D. 8; A. 7-9; P. 10; V. 6; scales 

 57-60; predorsal scales 49-54; scales around trunk middle 42-44; 

 snout If in head; eye U to opercle; interorbital yV- 1; length 213- 

 449 mm. Battle Creek in upper Missouri basin 2. No. 16,958, A. N. 

 S. P., type of C. productus Cope, dry skin (figured). 



Cylindrosteus agassizii Dumenl. PI. XXXVIII, fig. 12. 



Head 3f ; depth 2f in head; D. 8; A. 7; P. 11; V. 6; scales 55; 

 predorsal scales 47; scales around trunk middle 40; snout If in head; 

 eye H to opercle; interorbital £; length 420 mm. Dry skin, "North 

 America." 



Cylindrosteus castelnaudii Dumenl. PI. XXXVIII, figs. 13, 14. 



Head 3£; depth 2; D. 9; A. 8; P. 11; V. 6; scales 58; predorsal 

 scales 52; scales around trunk middle 45; snout If in head; eye 

 2f to opercle; interorbital |; eye in interorbital 2f; length 600 mm. 

 W. coast of Fla., in 1886, by Prof. A. Heilprin 1. 



This example agrees with Dumeril's account, which seems to be 

 the earliest name for the species. Possibly Lepidosteus (C.) latirostris 

 Girard is also identical, but the account of that species is insufficient. 

 C. bartonii D. is another synonym. 



Cylindrosteus megalops sp. nov. PI. XXXVIII, figs. 15, 10. 



Head 3f; depth If in head; D. 7, i, fulcra 2 ? (damaged); A. 8, i, 

 fulcra 8; P. 9, fulcra about 8, weak and indistinct distally; V. 6, 

 fulcra 5; scales 57 in 1. 1. to caudal base; predorsal scales about 51; 

 scales around trunk middle 44; snout If in head; mandible 2; inter- 

 orbital 5; pectoral 24; ventral 2\; snout width at rictus 4f; eye 

 H to opercle. 



Body moderately elongate, well compressed, predorsal region 

 stoutest in width, and greatest depth at ventral base. Caudal peduncle 

 well compressed, least depth If its total length. 



Head well depressed, much wider than deep, upper profile slightly 

 concave, especially about middle of snout. Lower profile similarly 

 approximated, and flattened head sides slightly convergent below. 

 Snout well depressed, arising in gentle median slope behind, and 

 width at tip trifle less than half of basal width. Eye large, trifle ellipti- 

 cal, placed about last § in head length, and H in least interorbital width. 

 Mouth completely closing, and truncated mandible tip included well 

 within snout tip. Series of minute sharp conic teeth along each edge 

 of jaw externally of more or less unequal size. Just inside small teeth 

 a single series of enlarged slender conic teeth, towards front of jaw 



