FISHES OF THE PHILIPPINE ISLANDS AND ADJACENT SEAS 193 



DirrJiizodon Klunzinger, Verb, zool.-bot. Ges. Wien, vol. 21, p. 664, 1871'. (Type, 

 Dirrhisodon elongatus Klunzinger, monotypic.) 



Body elongated, slender. Head with slightly convex profile. 

 Snout rounded in front, little wider than long. Teeth elevated, tri- 

 angular, mostly curved or inclined backward, toward apex both 

 coronal edges becoming coarsely serrated; root divided into two di- 

 vergent branches; upper teeth relatively large, broad, flat; front 

 lower teeth slender, subulate, curved inward, without denticles or 

 only one or two minute basal points. Nasal flap distinct. Inter- 

 orbital level. Gill openings wide. Spiracle one-fourth of eye, one 

 diameter behind eye. First dorsal close behind pectoral base ; second 

 dorsal over anal. Caudal with upper lobe much longer, notched 

 near end. Pectorals moderate. 



One species known from the Ked Sea and several from Cretaceous 

 and later formations. 



HEMIPRISTIS ELONGATUS (Klunzinger) 



Dirrhizodon elongatus Klunzinger, Verb, zool.-bot. Ges. "Wien, vol. 21, p. 665, 

 1871 (type locality: Red Sea). — Beusina, Glasnik Naravosl. Druztva, vol. 

 3, p. 225, 1888 (Red Sea). 



Depth 9; head 6, width 1. Snout 3% to 4 m head, I/2 to % 

 postocular part of head; front of lower lip with lobe and upper lip 

 with 3 grooves from angle; teeth in 13 + 13 rows, mostly 6 rows 

 inside; interorbital 5. Last gill opening above pectoral, each gill 

 opening 3 times high as eye. 



Scales with 3 to 5 keels. 



First dorsal begins above hind angle of pectoral; second dorsal 

 moderate, 2 to 2I/2 times lower than first dorsal; anal somewhat 

 smaller, begins below middle of second dorsal ; caudal length nearly 

 equal to both dorsals, upper lobe 3 times longer than lower and sub- 

 caudal very curved ; pectoral not quite twice long as high, not smaller 

 than first dorsal, similar and deeply concave; angles of all fins 

 pointed. 



Back slate-gray. Belly white. Fins gray, hind tips of anal 

 white. Length, 2.3 m. (Klunzinger.) 



Red Sea. 



Genus TRIAENODON MuUer and Henle 



Triaenodon Mullee and Henle, Sitz. Ber. Akad. Wiss. Berlin, 1937, p. 117. 

 (Atypic: Type, Carcharias oiesus Riippell; Arcb. Naturg., 1837, pt. 1, p. 

 396. Atypic: Type, Carcharias cbesus Riippell, Syst. Beschr. Plagiostomen, 

 p. 55, 1841. Type, Carcharias oiesus Riippell, designated by Jordan, 

 Genera of Fishes, pt. 2, 192, 1919.) 



Body rather slender, tapers to head and tail. Head wide, nar- 

 rows forward from broad convex crown. Snout short, wide, de- 

 pressed. Eyes small, lateral with nicitating membrane. Mouth 



