186 THE PLAGIOSTOMIA. 



than the end of the base of the second dorsal, beloAv the end of the free extremity 

 of the latter. Base of anal less than its length forward from the origin of the 

 subcaudal, which latter is reached by the inner angle of the fin. Caudal shorter 

 than the head; subcaudal deep, short, hind margin nearly vertical, straight. 

 Pectorals large reaching beyond origin of ventrals. 



Brown, wdth a transverse band of darker across the orbits, widening upon 

 the cheek; another band in front and one behind the ventrals, one through the 

 second dorsal and one in front of the anal, less definite than the anterior. 



New South Wales. 



Centeacion francisci. 



Plates 45-46. 



Ceslracion francisci Girard, 1854-, Proc. Acad. nat. sci. Phil., p. 196; 1858, Rcpt. Pacif. R. R. Fish., 



p. 365; GuNTH., 1870, Cat. fishes Brit, mus., 8, p. 416. 

 Heterodontus francisci Gill, 1860, Amer. journ. sci., ser. 2, 30, p. 281; Maclay & Macleay, 1878, Proc. 



Linn. soc. N. S. W., 3, p. 315, pi. 26. 

 Gyro pleurodus francisci Gill, 1862, Proc. Acad. nat. sci. Phil., p. 330, 490; Jordan & Gilbert, 1882, 



Bull. 16, U. S. nat. mus., p. 33; Jord. & Everm., 1896, Bull. 47, U. S. nat. mus., p. 20; Regan, 1908, 



Ann. mag. nat. hist., ser. 8, 1, p. 494. 

 Heterodontus {Ceslracion) francisi Dumeril, 1865, Elasm., p. 426. 



Head short, angular, with strong orbital ridges, divergent backward, ending 

 abruptly behind the occiput in young, less so in old. Crown concave transversely. 

 Snout short, steep, blunt. Nostrils near the end of the snout, connected with 

 the mouth by nasoral grooves; anterior nasal valves narrow, reaching the mouth, 

 not connected across the internarial space, curving outward posteriorly^, posterior 

 forming a fold at the outer side of the nostril and curving inward posteriorly to 

 meet the upper labial fold on the outer side of the nasoral groove. Mouth 

 narrow, with short labial folds on both jaws, lower widely separated behind the 

 symphysis, upper extending about three fifths of the distance from the angle to 

 the narial valve. A short groove behind each angle of the mouth. Anterior 

 teeth small, compressed, with about five cusps, median largest; with age the 

 outer cusps become less apparent and the median cusp much stronger. Some 

 of the molars are much elongated on large examples, nearly three times as long as 

 wide; all of them have a longitudinal keel, with age they become wider and 

 make more of an approach toward those of the other branch of the same jaws. 

 The symphyses are shorter in the young than on older individuals. Eye small, 

 lateral, farther back than the mouth, without nictitating membrane or fold. 

 Spiracle small, below and little behind the eye. Anterior gill opening three 

 times as wide as the posterior, width of the latter nearly equal to the length of 



