8 



UNITED STATES AND MEXICAN BOUNDARY. 



The body, when viewed in profile, is more elliptical, more elongated proportionally, than in 

 P. speciosus. The head constitutes rather more than the third of the length, the caudal fin 

 being excluded, The eye is of medium size and sub-circular ; its diameter entering three times 

 and a half in the length of the side of the head, less than once in advance of its anterior rim. 



more 



on the opercle. The mouth is larger than in 



mentioned 



the posterior 



extremity of the maxillary extending to a vertical line intersecting the anterior rim of the 

 orbit. The opercular flap is elongated, sometimes considerably developed, being prolonged 

 posteriorly and inclining downwards without tapering. This feature is quite peculiar to this 



species* 



The ventrals and pectorals are elongated, the latter not extending quite as far back as the 



former, which, however, overlap the vent and reach the origin of the anal fin. 



Br. VI : VI ; D X or XI, 11 ; A III, 10 ; C 4, 1, 8, 7, 1, 3 ; V I, 5 ; P 14. 

 The scales in the first variety (figs. 6 — 8) are as deep as long upon their posterior margin, 

 which is sub-truncated ; they are narrower posteriorly and rounded. In the second variety 

 (figs. 2 — 4) they do not taper off posteriorly. The radiating furrows and the pectinations are 

 numerous, each upon their respective section. 



The 



form 



patch 



fallax ; two of its extreme forms are represented on 



efastus. They 



are both figured size of life. 



List of specimens. 



Catal. 

 No. 



446 

 447 



448 

 449 



4.10 



451 



No. of 

 spec. 



Ag 



I 



1 



5 



10 



24 

 12 



Young. 



• .do. . . 

 Adult. 

 Young. 

 i . .do. . . 

 • .do. • • 



Locality, 



When 

 collected 



» 



Eagle Pass ....... 



San Felipe, Texas. 



Rio Cibolo, Texas., 

 Rio Nueces, Texas 



Rio Sabinal, Texas 



••••»•• «GO 



1853 

 1851 

 1851 

 1851 

 1854 

 1854 



Whence obtained. 



Maj. Emory 



Col. J. D. Graham 



Orig. 

 No. 



Nature of 

 specimen. 



do 



do 



Maj. Emory 

 do.. 



62 

 61 



Alcoholic. 



do 



do 



do 



t • .do. • 



do 



Collected by 



A. Schott 



Jno. H. Ciark 



do 



do 



Dr. C. B. Kennedy 



do 



Plate 



4. POMOTIS FALLAX, B. & GL 



•8, & Plate III, Figs. 9—12. 



Spec. Char.— Body sub-circular or sub-elliptical ; head moderate ; snout bluntly sub-conical. Mouth large ; posterior 

 extremity of maxillary extending to the anterior rim of the pupil. Eye moderate. Edge of preopercle not crenated. Auricular 

 flap very large. Spinous portion of dorsal of medium height, its origin situated opposite the base of the pectorals ; caudal 

 cmarginated posteriorly. Blackish or reddish brown, lighter beneath than above. Sides of head with bluish spots, sometimes 

 confluent into irregular lines. A black spot upon the base of the dorsal Cn. 



Sin.— Pomotis fallax, B. & G. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 24. 



Pomotis eonttxifrons, B. & G. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 24. 



A comparative study of a larger number of specimens than we had heretofore has satisfied us 

 that P. convexifrons was identical witli P. fallax. The latter appears to be one of the most 



