CESTRACION TUDES. 159 



a blackish spot on the upper angle of the second dorsal, on the lower angle of the 

 subcaudal lobe and on the tip of the tail. 



Society Islands, collected by Andrew Garrett. 



CeSTRACION TUDES. 



Cornuda Parra, 1787, Hist, nat., p. 71, pi. 32. 



Zygaena tudes Valenciennes, 1822, Mem. Mus. hist, nat., 9, p. 225, pi. 12, f. 1; Gunth., 1870, Cat. 



fishes Brit. mus.. 8, p. 382; Moreau, 1881, Poiss. France, 1, p. 327; Doderlein, 1881, Man. ittiol. 



Medit., 2, p. 50. 

 Sphyrna tudes Muller & Henle, 1841, Plagioa., p. 53. 

 Sphyrnias tudes Gray, 1851, Chondropterygii, p. 53. 

 Cestracion {Zygaena) tudes Dumeril, 1865, Elasm., p. 384. 

 Sphyrna (Platysqualus) tudes Jord & Everm., 1896, Bull. 47, U. S. nat. Mus., p. 44. 



Head and hammer more exactly transverse than in C. zygaena; hind mar- 

 gins of the hammer at right angles to the longitudinal axis; front margin much 

 curved, undulated, with a shallow concave indentation above the nostril, front 

 outline forming a segment of a circle the centre of which is about opposite the 

 fifth gill openings, the curve continuing in sharper curves around the lateral 

 edges of the hammer and the hinder angles to the nearly straight hinder edges. 

 Width of oculonarial expansion, near the mouth, about equal to its length behind 

 the nostril across the end. Nostrils with a groove toward the middle of the 

 snout; in cases, perhaps fresher specimens, the groove is filled and hardly visible. 

 Eye small, one diameter of the orbit from the nostril. Mouth large, length half 

 the width, or three sevenths of the length of the snout. Teeth unlike, in §5 rows; 

 bases broad somewhat swollen, two-rooted; cusps narrower, upper oblique with 

 a sharp notch on the outer edge; lower cusps narrower, more slender, more erect, 

 especially toward the middle of the mouth where the teeth resemble those of 

 species of Isurus; median teeth of the upper jaw and the median tooth of the 

 lower quite small. Dorsal origin slightly behind the base of the pectoral; fin 

 large, triangular, height little greater than the length, upper angle sharp, hind 

 margin not greatly concave; base two and one fifth times in the distance from the 

 second dorsal; end of the fin reaching a vertical from the ventrals. Ventrals 

 in front of the mid length. Second dorsal small, base above the hind half of 

 that of the anal, upper angle rounded. Anal elongate, lower angle produced, 

 hind margin concave, base one and one half times in its distance from the caudal. 

 Caudal two sevenths of the total, subcaudal lobe strong, produced, slightly 

 blunted. 



Total length 35, snout to abdominal pores IG, snout to fifth gill opening 7|, 

 snout to first dorsal IO5, snout to mouth 21, greatest width of head Si, and 

 length of caudal 10 inches. 



