FISHES STURIONIDAE ACIPENSER ACUTIROSTRIS. 



355 



The monograph of the sturgeons (Adpenser) by Fitzinger and Heckel is replete of informations 

 upon the natural history of these fishes. The species of the Old World especially are treated 

 of with much detail, while a good deal is~yet untold respecting those of the New World. 



The short-nosed sturgeon, so abundant in the waters of California, and described under the 

 name of 



ACIPENSER BRACHYRHYNCHUS, Ay re 8, 



in the Proceedings of the California Academy of Natural Sciences, I, 1854, 16, has not fallen 

 under our observation. It is so much more to be regretted, as its natural affinities seem to 

 bring it nearest to A. transmontanus, which we lack also in good specimens. 



1. ACIPENSER TRANSMONTANUS, Richards. 



Columbia River Sturgeon. 



SYN. Adpenser transmontanvs, RICHARDS. Faun. Bor. Amer. Ill, 1836, 278, pi. xcvii, fig. 2. DEKAY, New Y. Faun. 

 IV, 1842, 347. STORER, Synops. 1846, 248. GRD. in Proc Acad. Nat. Sc PJiilad. VIII, 185G, 137. 



Not in possession of any other specimen but a dried skin about thirty -seven inches in total 

 length, we refrain entering into any details as regards its structure. The species is a very 

 characteristic one, and which requires to be carefully re-investigated in order to furnish us with 

 new data in the determination of the species recently observed along the coast of California, 

 within its bays and the lower waters of its rivers. 



List of specimens. 



2. ACIPENSER ACUTIROSTRIS, Ay res. 



SPEC. CHAR. Body sub-fusiform in profile. Head slender, upper surface nearly plane, depressed, declivous, with a shallow 

 frontal groove. Snout tapering and acute. Mouth large; lips simple. Barbels filiform, simple, nearer the mouth than the 

 apex of the snout. Ten or eleven dorsal shields from the occiput to the anterior margin of the dorsal fin ; twenty-six to twenty- 

 seven shields in the lateral series, and nine or ten between the pectorals and the ventrals. All these shields being rather close 

 to one another, although not quite contiguous. First dorsal shield united to the cephalic cuirass. 



SYN. Jlcipenser acutirostris, AYRES, in Proc. Cal. Acad. Nat. Sc. I, 1854, 15. GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 

 1856, 137. 



The museum of the Smithsonian Institution has in preservation a specimen of this species 

 about twenty inches in total length, brought home by Lieutenant Williamson s party ; and 

 another specimen about thirteen inches long, sent by Dr. Ayres himself. Both of these 

 specimens, therefore, are larger than the one originally described by the latter gentleman. The 

 snout in the younger specimen is proportionally more slender and more acute still than in the 

 older one. The head forms about the fourth of the total length, somewhat more or less 

 according to age. A shallow groove may be observed along the middle region of its upper 

 surface which is gradually sloping from the occiput to the extremity of the snout. The eyes 

 are snb-circular and of moderate development, situated midway between the apex of the snout 

 aiid the posterior edge of the opercle. The barbels are nearly equal in length and inserted 



