GILBERT AND STARKS— FISHES OF PANAMA BAY 11 



the teeth in adults. Teeth in upper jaw ludadly trianmilar, in fnmt "f jaw nari'dwer and erect, those in 

 sides of jaw growing at once broader and more oblique. The lateral teeth have a strong notch on the 

 outer side. Both margins are strongly serrate, the serrations increasing toward base, one or more of 

 those below notch sometimes enlarged and cusp-like in adults. Teeth about ||. 



Conspicuous areas of large and of small pores on under side of head. Gill-openings of 

 moderate width, the longest equaling distance between eye and nostril, the fifth much shortened, about 

 I length of first. Eye small, equaling length of nasal opening, i^ to 2 in middle gill-slit. 



Pectoral short and broad, the posterior margin not strongly incurved. Tip of fin extending 

 to a vertical intersecting dorsal base at origin of its posterior third or fourth. Anterior margin of pec- 

 toral 3 times length of inner or posterior margin, the latter less than width of base. First dorsal 

 beginning behind a vertical from a.xil of pectorals a distance about equaling that which separates eye 

 from nostril. Free margin of fin gently concave, the anterior angle extending to a point midway 

 between base and tip of posterior lobe, when the fin is depressed. Base of first dorsal 2^ to 2^ in 

 interspace between dorsals. Base of second dorsal 7 in interspace between dorsals, 2^ in its distance 

 from anterior margin of pit. The origin of second dorsal falls over or behind middle of anal base. 

 The fin is but slightly concave, with rounded anterior angle; its posterior angle much produced; the 

 posterior margin exceeding base of fin, which about equals length of anterior margin. Anal inserted 

 more anteriorly than second dorsal, its base longer, its margin much more deeply concave, the length 

 of base contained about i| times in its distance from lower caudal lobe. Lower caudal pit in advance 

 of the upper. The cauilal is broad throughout, the lower lobe not falcate, slightly less (y'j to \) than 

 half length of ujiper loiie, which is about 4^ in total length. Shagreen coarse. 



Color varying from light to dark gray above, the belly and lower part of sides whitish. Fins 

 all dusky or grayish, the caudal often with a blackish border. Pectorals with or without a black tip, 

 the latter when present not as conspicuous as in C. athalonis, usually not extended onto inner face of 

 fin. A specimen 73 cm. long has the claspers undeveloped, extending slightly beyond margin of 

 ventrals. Another specimen, 85 cm. long, has the claspers fully developed, extending beyond the 

 margin of the ventrals for a distance of 5 cm. 



Abtiiidant at Panama, where numerous specimens were secured. 



C. cerdah strongly resembles C- (cthalorua, with which it is associated in the 

 Bay of Panama. It is distinguishable at sight by the narrower gill-slits, broader and 

 less falcate fins, and by the much less conspicuous black tips to the pectorals. The 

 dentition is very dissimilar in the two, and makes it necessary to arrange them in 

 different parts of the genus, C. cerdale belonging to the subgenus Platypodon. 



8. Carcharias azureus sp. nov. 

 Cazon Azul. 



Plate II, Fig. 5. 



.Snout very short and bluntly rounded, its outline nearly parallel with cleft of mouth, the length 

 of its [M'eoral portion if to i| in distance between angles of mouth, constantly greater than distance 

 from chin to line joining angles of mouth, and very slightly {if to y'j) less than distance between 

 inner angles of nostrils. Width of snout opposite nostrils equals distance from angle of mouth to first 

 gill-slit. Eye nearer mouth than nostril, nearer nostril than angle of mouth. Outer angle of nostril 

 midway between tip of snout and middle of eye. Eye small, its horizontal diameter | nostril opening. 

 Nostrils converging along lines whicli meet a short distance behind symphysis. The anterior margin 

 is produced into a short, triangular flaj). Width of mouth equaling half length of head in front of 

 gill-slits. Gill-slits wide, equaling or slightly exceeding the distance from eye to nostril, about equaling 

 length of branchial area. Two very short diverging furrows visible at angle of mouth, one representing 

 as usual the obsolescent upper lip. 



