178 THE PLAGIOSTOMIA. 



Total length 25?, snout to abdominal pores llj, snout to fifth gill opening 

 4|, snout to mouth 2§, and caudal 5j inches. 

 San Diejro, California. 



Galeorhinus dorsalis. 



Mustelus dorsalis Gill, 18G4, Proc. Acad. nat. sci. Phil., p. 149; Jordan & Gilbert, 1882, Proc. U. S. 



nat. mus., 5, p. 109. 

 Mustelus mento Cope, 1877, Proc. Amer. philos. soc, 17, p. 47. 



f Mustelis edvlis Perez, 1SS6, Estud., p. 4; Philippi, 18S7, Ann. Univ. Chile, 71, p. 15, pi. 6, f. 5. 

 Galeus dorsalis Jord. & Evebm., 1896, Bull. 47, U. S. nat. mus., p. 30; Gilbebt & Staeks, 1904, Mem. 



Cal. acad. sci., 4, p. 7, pi. 1, f. 2. 



Head tapering from the spiracles; snout rather sharp, blunted at the end. 

 Nostrils near the mouth, entirely behind the mid length of the snout; anterior 

 valve with a produced rounded lobe. Eyes small, length of orbit less than one 

 third of that of the snout. Mouth moderate, width less than the preoral length 

 of the head; labial folds rather short, lower a trifle the longer. Teeth differing 

 on the two jaws: upper cusps oblique, apex sharply produced, inner edge straight 

 or slightly concave, outer edge deeply notched; lower cusps more erect, less 

 produced, with a concavity on each edge, rendering some of the teeth tricuspid. 

 ,The lower teeth resemble those of G. laevis. Widest gill opening equal to more 

 than length of orbit. Pectorals broad, obliquely subtruncate, angles rounded, 

 inner broader, fin applied to the side reaching little behind the middle of the base 

 of the dorsal. Origin of the dorsal about half way from the end of the base of 

 the pectoral to the inner pectoral angle, length of dorsal base two thirds of the 

 interdorsal space, hinder extremity reaching nearly or quite to a vertical from 

 the ventrals, hind margin more oblique than that of the second dorsal. Second 

 dorsal about half as large as the first, base three fourths as long and equal the 

 distance from the caudal, hind margin little more erect than in first dorsal. 

 Anterior four fifths of the anal base below the hindmost two thirds of that of the 

 second dorsal, base of anal one and one half times its distance from the caudal. 

 Caudal one fifth of the total length ; subcaudal lobe slightly produced. 



Olive to greyish brown on the back and fins; lower surfaces, from the eye 

 and upper parts of the gill openings, white. 



Total length of specimen described 19§, snout to abdominal pores 10, snout 

 to fifth gill opening 4j, snout to mouth l\ and length of caudal 4 inches. 



Panama. 



