FISHES OF NEW ZEALAND. 75 



Order II.— PLAGIOSTOMATA. 



From five to seven gill openings ; jaivs distinct from the skull. 



Sub-order.— SELACHOIDEL— Sharks. 



Body more or less ci/lindincal, gradually ])assi7ig into the tail ; gill 



openings lateral. 



CARCHARIID^. 



Eye with a nictitating membrane ; moutli crescent-shaped, infei-ior . 

 two dorsals, the first opposite to the space between the pectoral and 

 ventral fins, without a sjiine ; an anal fin. 



Carcharias. 



A pit at the root of the caudal ; no spiracles ; the labial fold does not 

 extend much beyond the angle of the mouth ; snout produced ; teeth 

 with a single sharp cusp, more or less dilated, and triangular. 



Seas of the temperate and trojiical regions. 



120. CARCHARIAS BRACHYURUS. Gunth. 



Blue Shark. 

 C tnelanopterus, Cat. Col. Mus. % C. brachyurus, Glinth., VIII., 3G9. 



Snout rather pointed, the distance between the end and the mouth beicg 

 more than the length of the mouth, and aboiit two-thii-ds its width . 

 teeth in the upper jaw oblique, serrated on both margins, and with a 

 deep notch on the outer margin ; teeth of the lower jaw narrow, erect, 

 lanceolate, serrated, on a broad two-rooted base ; pectorals narrow, 

 pointed, falciform ; dorsal rather nearer to the pectorals than the 

 ventrals ; second doi-sal very small ; origia of the anal opposite to that 

 of the second dorsal, and midway between the ventral and caudal. 



Color uniform (Giinth.) 



New Zealand (British Museum), Australia. 



I have seen no specimens. 



ACANTHIAS, 



Two dorsals, each with a sj^ine ; teeth equal in both jaws, rather 

 small, their point is so much turned aside that the inner margin of the 

 tooth forms the cutting edge ; spiracles rather wide, immediately behind 

 the eye ; gill openings narrow. 



Temperate sea.s of both hemispheres. 



