|b.l324. ELASMOBRANCHIATE FISHES— JORDAN AND FOWLER. 621 



19. MITSUKURINA OWSTONI Jordan. 



MitMtkimiin vivstoui Jordan, Proe. Cal. Ac. Sci., 1898, p. 200; Misaki. 



j Length of specimen, apparently 3^oung male, 42 inches!. Head (to 

 irst g-ill-opening) 4f in length; dej^th about 10; snout from eye If- 

 n head; from front of mouth 24; length of blade of snout from its 

 nsertion below If; length of gill area 2f ; depth of last gill 6; eye 

 12 in snout from eye; interorbital area 2|; spiracle a little smaller 

 ;han eye; length of one mandible 2f in head; length of maxillary 2|; 

 jectoral base If in length of pectoral fin, which is 2f in head; first 

 lorsal base If in its height, which is 2f in head; second dorsal l)ase 

 Lf in its height, which is 3 in head; ventral base 2 times its height, 

 ength of base 3 in head; claspers very short (perhaps immature), 

 learly 12 in head; anal base 2^ times its height and 2f in head; 

 oaudal, measured from above, 2f in length of body; greatest height 

 of lower lobe nearly 3 in head. 



Body elongate, compressed behind, fiesh and skeleton extremel}^ 

 limp, folding like a wet rag. Head moderate; snout produced in a 

 long, flat, flexible, leaf-like blade, somewhat like that of Polyodon 

 HpatkuJa ])ut narrower, more limp and more pointed; median line of 

 snout with a thick, rounded median keel; lower side of the blade free 

 for a considerable distance backward from upper jaw, almost to eyes; 

 eye small, without nictitating membrane; mouth inferior, with elon- 

 gate cleft; dentar}" bones broad, loosely connected, movable, capable 

 of being spread wide apart, but normally lying close together and 

 nearly parallel; a notch at S3aiiphysis, tip of lower jaw strongly curv- 

 ing upward and inward; similar notch at tip of upper jaw between 

 rather loosely joined maxillar}-; middle of each jaw without teeth in 

 front; teeth few-rowed, about || on each side, all needle-shaped, verj'- 

 slender, pointed, more or less curved backward and inward; each tooth 

 with a two-rooted base, large teeth in front simple, smaller ones on 

 sides of jaws each with two small basal cusps; second and third tooth 

 of lower jaw longest; the second about as long as eye; first and second 

 tooth of upper jaw similar to these but somewhat shorter; lateral teeth 

 of both jaws progressively smaller, ))ut all slender and sharp; nostrils 

 large, about as large as eye, their distance from (>.ye twice the eye; 

 each nostril with a small notch on lower edge and a free flap within. 

 Spirach^ large. Gill-openings about equal in height, the last above 

 base of pectoral. 



Skin everywhere rough, the scutes very small, granulated No 

 lateral line or conspicuous nuicous pores. 



Fins all thin, flexible, papery, the broad bones somewhat exserted 

 from soft flesh; first dorsal short, moderately high, not emarginate, 

 the insertion above axil of pectoral, second dorsal lower, remote from 

 Hrst, interspace H in head, the insertion m^aily midway between 



