74 BULLETIN OF THE BUREAU OF FISHERIES 



first, with straight margin. The small caudal fin is demarked from the second dorsal 

 by a deep notch; it is lanceolate in outline, terminates rearward as a short whipUke 

 filament, and extends a short distance forward on the ventral surface of the trunk, 

 there being no separate anal fin. The ventrals and pectorals are both triangular 

 and pointed, the latter being much the larger and reaching back nearly to the point 

 of origin of the ventrals. In the male the lower part of each ventral fin is modified 

 as a trifid clasping organ. The skin is smooth, or perhaps shghtly prickly, the 

 lateral Une well developed, ramifying in several branches over the head. 



This species^" is a close ally of the well-known chimasra of north Eiu'opean 

 seas (C. monstrosa), but is distinguishable from it by the facts that it has no separate 

 anal fin, that there is a considerable free space between its two dorsal fins, that the 

 outline of the second dorsal fin is straight, that its caudal filament is much shorter, 

 and that its pectorals hardly reach back to the ventrals. 



Color. — ^Leaden all over. 



Size. — Maximum length about 3 feet. 



General range. — Not uncommon on the continental slope of North America 

 from the latitude of Cape Cod northward, in 300 to more than 900 fathoms. 



Occurrence in the Gulf of Maine. — We mention the chimjera here because one 

 (or more) was brought in from Georges Bank some time between 1877 and 1880.°° 

 It would be no surprise to find them on the seaward slope of the bank, for halibut 

 fishermen have often caught them off LaHave and the more easterly banks. One 

 has even been found in the harbor of Noank (Conn.), but there is no record of it in 

 the inner parts of the Gulf of Maine. 



Habits and food. — Nothing whatever is known of the habits of this chimaera; 

 little more of the northern Eui'opean species except that it is a groimd fish, omniv- 

 orous, eating small fish, mollusks, Crustacea, echinoderms, and worms, and that it 

 produces large eggs with horny oval cases, bearing threadlike filaments. 



The bony fishes. Subclass Teleostomi 



THE STURGEONS. FAMILY ACIPENSERID.S 



The sturgeons — the only Gulf of Maine representatives of the ganoid fishes — 

 share with the sharks an uneven tail with the vertebral column extending out into 

 the upper lobe, but there is no danger of taking one for a shark as there is but one 

 gill opening on each side, and the gills are inclosed by bony gill covers. 



31. Sturgeon {Acipenser sturio Linnaeus) 



Jordan and Evermann, 1896-1900, p. 105. 



Description. — Sturgeons are easily distinguished from all our other salt-water 

 fishes by the fact that the head is covered by bony plates united by sutures, and 

 the skin is armored by a row of large bony shields or bucklers along the mid-back, 



- *• This flsh is generally considered identical with a chimaera taken ofl the coast of Portugal, hence the choice of the specific 

 ame affims instead of plumbea, by which the chimaera of North American waters was first known. 

 •* Report, U. S. Commission of Fisheries, 1879 (1872). p. 788. 



