1. ACIPENSER. 337 



than to tho oyc. Parietal plates consi-)icuously larger than temporal. 

 Osseous shields moderately developed, 12-14 on tho back, and 

 40-42 along the side. Skin densely eovercd with numerous larger 

 and smaller stellate ossifications. Length of the dorsal fin con- 

 spicuously more tliau its distance from the caudal, with 42-48 rays. 

 Tho greater part of the anal below the dorsal. The first caudal 

 fulcrum very small. 

 Adriatic. 



a. Stuflfed, 3 feet long. Purchased of Dr. J. Heckel. 



6. Acipenser brachyrhyTiclius. 



Acipenser bracbjTliynchus, Ayrcs, I'roc. Cal. Acad. Nat. Sc. 1854, 



p. IG. 

 (Antaceus) brachyrbyncbus, Dumcril, Noiiv. Arch. Mus. iii. 



p. IGU, pi. 11. fig. 1. 

 ( ) ayresii, Diimeril, I. c. p. 171, pi. 12. fig. 1, and pi. 16. 



%.3. 



Very closely allied to A. naccarii. Snout osseous above, rather 

 obtuse and short, its length being about one-third of the length of 

 the head. Barbels not flattened, simple, rather long, nearer to the 

 extremity of the snout than to the eye. Osseous shields moderately 

 developed, 11-12 on tho back, and 36 along the side. Skin densely 

 covered with numerous large and smaller steUate ossifications. 

 Length of the dorsal fin conspicuously more than its distance from 

 the caudal fin, with 42 rays. The greater part of the anal below 

 the dorsal. The first upper caudal fulcrum larrje, much larger than 

 the folloiviny. 



California. 



a. Two feet long. San Francisco. Presented by Dr. W. 0. Ayres 



as A. hrachyrhynchus. 

 b-d. In bad state. San Francisco. Presented by Dr. W. 0. Ayres. 

 e. Four feet long : stuffed. California. Presented by J. H. Gurney, 



Esq. 



7. Acipenser nasus.- 



Heckely Sitzgsber. Ak. Wiss. Wien, 1851, vii. p. 552, taf. 23 ; Heck. 

 (§• KncTj Siisswasserf. p. 3G0. 



Snout ivith a large os.feous shield above, pointed, rather produced, 

 equal in length to the postorbital part of the head. Barbies simple, 

 nearer to the eye than to the extremity of the snout. Osseous 

 shields well developed, 13 on the back, and 41 along the side. 

 Skin with numerous rough stellate ossifications unequal in size ; tho 

 ossifications of the front part of the abdomen are arranged like 

 ganoid scales. Part of the anal fin below the dorsal. D. 41. 

 (Meckel.) 



Known, apparently, from a single example, 26 inches long, from 

 Venice. 



8. Acipenser huso. 

 Hausen. 



? Jcbthyocolla, Bellnn. Be Aquat. i. p. 104; liomlcL De Pise. fiuv. 

 VOL. VIII. z 



