FISHES OF THE QVLF OF MAINE 73 



Occurrence in the Gulf of Maine. — The cow-nosed ray has even less claun to be 

 called a Gulf of Maine fish than have the sting rays just mentioned, for while it 

 is often taken in the traps at Woods Hole — 145 in one day on one occasion — and 

 is recorded from Nantucket, it has never actually been seen east or north of Cape 

 Cod. 



Chimseroids. Subclass Holocephali 



THE CHIMiERAS. FAMILY CHIM-ERID^ 



The chimseras find their nearest affinities in the sharks but are separated from 

 the latter by many important anatomic characters, the most obvious of which are 

 the facts that there is no spiracle, there is but one gill opening on either side, the tail 

 is symmetrical, and the gills are fringelike and free at the tips like those of bony 

 fishes. In general aspect the chimseras remotely suggest the grenadiers (p. 467), 

 but are easily separable from them by the location of the ventral fins, which are 

 set far ^back uiider or behind the tips of the pectorals; by the fact that the fin on 

 the back is separated by a deep notch into dorsal and caudal portions; by the very 

 small eye; and by the large size of the pectoral fins, to list only the most obvious 

 differences. There is no danger of confusing them with any other Gulf of Maine 

 fishes, so curious is their appearance. 



Fia. 31.— Chimsera (Chimscra affinis', 



30. Chimaera. {Chimsera affinis Capello) 



Jordan and Evermann, 1896-1900, p. 95. 



Description. — The chimtera is deepest (one-seventh to one-eighth as deep as 

 long) just behind the gills, tapering gradually backward to a weak slender tail, and 

 is very soft bodied. The head is short, its dorsal profile oblique and prolonged into 

 a short, soft, conical knob above the mouth. The forehead of the male bears a 

 curious cartilaginous hook, armed with recurved prickles on its lower surface, which 

 probably serve to clasp the female. The mouth is inferior in position, relatively 

 small, the upper jaw with four, the lower with two, flat plates, set edgewise, in place 

 of teeth, and with thick fleshy hps. The gill openings are vertical, set low down 

 on the sides of the neck, and each is covered with a flap of skin paralleling the 

 gill covers of bony fishes. 



There are two distinct dorsal fins. The first of these originates over the gill 

 opening, is triangular, about as high as long, and supported at its anterior margin 

 by a stout spine that is free at the tip. The second dorsal is separated from the 

 first by a space that probably varies in length, and is less than half as high as the 



