304 



U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



edges being linear, and would be parallel were the scales not tapering towards their anterior 

 concave margin just alluded to. Badiating furrows are observed upon the anterior section only. 

 The ground color is olivaceous brown ; the upper aspect of the head, the back,, arid the sides 

 are rather darker, resulting from crowded minute dots upon the scales, which dots are more 

 scattered over the flanks. The belly and the inferior surface of the head are unicolor, 

 yellowish. A black streak exists upon the middle of the flanks, from the anterior third of body 

 to the base of caudal fin, intersected by irregular transverse and elongated spots. 



List of specimens. 



Family ESOCIDAE, Bo nap. 



The upper arcade of the mouth is formed by the premaxillar in front, and the maxilar bones 

 laterally. The body is covered with scales. The dorsal fin is situated opposite the anal ; no 

 adipose fin being present. The pseudo branchia are glaudulous, not visible, being covered by 

 the mucous membrane of the respiratory apertures. The swimming or air-bladder is simple ; 

 its inner surface exhibiting a rete mirabile. There are no pyloric appendages and no cul-de-sac 

 to the stomach. 4 



SYN. Esoces, Cuv. Regn. Anim. II, 1817, 182; 2d ed. II, 1829; &, ed. illustr. Poiss. 229. MULL, in Wiegm. Archiv 



fur Naturg. 1843, I, 323 ; &, 1845, I, 132. Cuv. & VAL. Hist. nat. PoU. XVIII, 1846, 269. 



Esocidae, BONAP. Sagg. Distr. metod. Anim. Vertebr. 1831, 113. RICHARDS. Faun. Bor. Amer. Ill, 1836, 123. 

 , N. Y. Faun. IV, 1842, 222. STORER, Synops. 1846, 184. 



The pikes and pickerels which represent this family are all inhabitants of the fresh waters of 

 the temperate zone. The genus Esox is the only one of the family as recently limited by the 

 late Prof. Joh. Miiller. 



A few specimens of the latter genus were collected, under Lieut. A. W. Whipple, by Dr. 

 George Gr. Shumard, near Fort Smith, Arkansas ; and by H. B. Mollhausen in Coal creek, 

 Arkansas, and twenty miles west of (jhoctaw Agency. A more minute investigation of these 

 specimens is temporarily deferred until a larger collection shall enable us to monograph the 

 genus, a task which could not be attempted under the present circumstances. 



Family SALMONIDAE, Bonap. 



In this family the upper arcade of the mouth (upper jaw) is formed anteriorly by the 

 premaxillar (intermaxillar bones), and laterally by the maxillaries, the dentition varying 

 according to the genera. The body is always covered with scales. There is also an adipose fin. 

 Pseudo branchia or accessory gills are present in all. Numerous pyloric appendages may be 

 observed. The swimming or air bladder is simple, there being no oviduct ; the eggs, upon 

 leaving the ovaries, are dropped into the abdominal cavity, whence they find an exit through a 

 post-anal aperture provided to that effect. 



