358 



U. S. p. E R. EXP. AND SURVEYS ZOOLOGY — GENERAL REPORT. 



Sru. —Polyodon, Lackp. Hist. nat. Poiss. I, 1798; &., ed. 8vo. I, 1819,309.— lUrm. Ichth. Ohiens. 1820, 82.— Cuv. Rtgii. 

 Anim. II, 1817, 142; 2d cd. II, 1829; &, ed. illustr. Poiss. l.W.— Stoker, Synops, 1846. 249. 

 Spalularia, SiiAW, Gen. Zuol. \', 18U4, 3()2. — DuM. Iclitliyol. aiiulyt. 185G, 1.55. 



Tliis genus appears to be very clo.sely allied to Flanirostra, which, however, we have not been able 

 to compare it to, having had no specimens of the latter genus at our command. Our compara- 

 tive studies, therefore, rest solely upon the descriptions of Lesueur and Eafinesque. Dr. Kirt- 

 land's own account of Flanirostra had to be drawn up from published data, he never having 

 had the opportunity of examining that fish. 



POLYODON FOLIUM, Lace p. 



Paddle-Fish. 



Spec. Char. — Body sub-cylindrical, compressed, tapering from the thorax to the tail. Head sub-conical, expanding liori- 

 zontaliy into a spatuliform snout, constituting altogether more than the half of the total length, the snout itself exceeding in 

 length the remainder of the head, or head, properly so-called. Eyes very small and circular, situated opposite the extremity 

 of the lower jaw. The membranous expansion of the opercle or accessory gill cover extends as far as the origin of the ventral 

 fins. Above, steel blue; white beneath; gill covers maculated by stellate impression. 



SiK.—Polyjodon folium, Lacep. Hist. nat. Poiss. I, 1798; &, ed. 8vo. I, 1819, 309, PI. xiii, fig. 3 — Rafin. Ichth. Oniens 

 1820, 83.- Cuv. Regn. Anim. II, 1817, 143 ; 2d ed. II, 1829; &, ed. illustr. Poiss. 352— Mitchill, Hii.- 

 DRETH & Clemens, in Amcr. Journ. of Sc. and Arts, XII, 1827, 201, 202, and 204. — Kirtl. in Host. Journ. 

 Nat. Hist. IV, 1842, 21, PI. ii, fig. 1.— Griff. Ci<i>. Anim. Kingd. X, 1834, 591.- Storer, Synops. 

 1846, 249. 



SpahiUiria reticulata, Shaw, Gen. Zool. V, 1804, 362, PI. clvi. 



Paddle-fish; Spoon-hilled Sturgeon, Vernacular. 



Tlie specimens submitted to our examination are all immature, measuring from five to seven 

 inches in total length. We have ascertained the presence of spiracula, one on either side, 

 occupying the same positon as in the sturgeons, close to the outer edge of the tympanic bone, 

 between the latter and the gill covers. Whether pseudo-branchiae exist or not we have not yet 

 had the opportunity of ascertaining. 



List of specimens. 



