2. SCAPHIEHYNCnUS. 345 



Acipenser (Antaceiis) alexandri, Dmnfril, I. c. p. 183, pi. 15. fig. 1. 

 ( ) oligopeltis, Dumeril, I. c. p. 184, pi. 1-5. tig. 2. 



Snout long, rather longer than the remaining part of tlie head ; 

 harhels simple. Osseous shields well developed, *J-1 1 on the back, 

 27-29 * on the side, and 9-10 on the abdomen. Skin with nume- 

 rous stellate ossifications, unequal in size. Part of the anal fin 

 below the dorsal. D. 30-37. 



California. 



2. SCAPHIRHYNCHUS. 



Scaphirhynchus, Hcckely Ann. Wien. Miis. i. 183''5, p. 71. 



Posterior part of the tail attenuated and depressed, bo that it is 

 entirely enveloped b}' the osseous scutes. Spiracles none. The 

 caudal rays do not extend to the extremity of the tail, which termi- 

 nates in a filament. 



Mississippi and tributaries. 



1. Scaphirhynchus cataphr actus. 



Acipenser cataphractus, G7-ay,Proc. Zoul. Soc. 1S'S4, p. 122. 

 Scaphirhynchus rafinesquii, Ifeckcl, I. c. pi. 8 ; Bnitzcr, Ue Sc, r. dis- 



quisitiunes anatomiccc, DisHcrt. Dorpnt. 18(;0. 

 Acipenser platorhvnclms, {Itafincsque) Kirtland, Bost. Jowm. Nat. 



Hid. V. p. 25, pi. 8. fig. 1. 

 Scaphirhynchus platirhynchus, Girard, U. S. Pac. R. It. Exp. Fish. 



p. 357. 



Snout spatulate ; 15-16 scutes along the ba«k, 40-46 on the side, 

 and 10-13 along the abdomen. 

 Mississippi and tributaries. 



a-h. Stuffed, 4 and 2t} feet long. Ohio. 



c. Fine specimen. New Orleans. Purchased of Mr. Cuming. 



d. Half-grown. North America. Purchased of Mr. Brandt. 



e. Half-grown : stuffed. North America. 

 /. Adult: skeleton. 



* The number 49 is a misprint in Dr. Ayres's doscription. 



