1. ACU'ENSKR. 343 



/5. Synonymy of examples of the New World. 



Acipenser oxjrhynclms, Mitch. Trans. Lit. (§• rhil. Sac. N. York, i. 



p. 4(52; Lcsiteitr, Trans. Am. Phil. Soc. now ser. i. p. 394; Delcn;/, 



Nvtv York Faun. Fish. p. 'MO, pi. 58. iig. 189; Aijres, Bost.Jonni. 



Nat. Hist. iv. p. 287 ; Storer, Mem. Am. Acad. ii. p. 499, and viii. 



p. 4;il (pi. 35. lig. 4); Fitz. ^- Heck. Ann. Wien. 3Ius. i. d. 28G. 

 Iluso o.vyrliynclius, Dumeril, Nouv. Arch. Mus. iii. p. 159 (name 



only). 

 ? Acipenser (Antaceus) hallowellii, Dimidril, I. c. p. 172 (probably an 



old example). 

 Acipenser (Autaceus) lecoutei, Dumeril, I. c. p. 177, pi. 16. fig. 1. 



Snout pointed, produced, it being equal to, or but little shorter 

 thfin, the remaining part of the head in examples to 3 feet long. 

 Earbels nearer to the eye than to the extremity of the snout ; in very 

 large examples, especially those with a broad snout, the barbels are 

 midway between snout and eye, or even nearer to the end of the 

 snout. Osseous shields well developed: 11-13 along the back, and 

 (34) 29-31 (in young examples sometimes 26 or 27) along the side* 

 Skin with very small rough points in very young examples f; in 

 older ones these ossifications are broader, rough, substellate, and 

 more J or less § regularly arranged in oblique series. Anal fin below 

 dorsal. D. 37-44. 



Mediterranean ; Western and Northern Europe ; Eastern North 

 America. 



a. Earopedn examples. 



a. Stuffed, 8 feet long. German Ocean. — Eack and abdomen with 

 rough, rather irregular, stellate or scale-like ossifications. 



h. Skin of a lai'gc example, with stellate ossifications, irregular in 

 arrangement and size, on the back and abdomen. 



c, d-ij. Heads of large examples, in spirits. German Ocean. 



h. Very large head, 19 inches long {A. latirostris). 



i. Upper part of a very large head, 20 inches long (A. latirostris). 

 lierwick-upon-Tweed. 



Jc. Stutt'ed, 6 feet long. Thames. Purchased of the Zoological So- 



* Whilst, according to my observations, tlie rudimentary ossifications of the 

 inti'guuients are subject to much variation with regard to development and ar- 

 ranjicuK'nt in this and in other species, tiie numbers of the dorsal and lateral 

 bucklers are very constant. I give here the numbers of seventeen European 

 examples : — 



Adult and lialf-grown. 



13 + 34 (lilack Sea) 

 12 4- 31 



12 + 31 

 11 + 31 

 11 + 31 



13 + 30 (Black Sea) 

 13 + 29 

 13 + 29 



In American examples T count 11-12 + 27-29. 

 f Hh^o. Dumeril. | Acijumrr, Dumeril. 



