NO. 1324. ELASMOBRANCHIATE FISHES— JORDAN AND FOWLER. 007 



I Japan to Australia, rather common to the southward. Our speci- 

 mens from Nagasaki, and one from Haktita, where it was found abun- 

 dant. The identity of the Japanese species with the Australian 

 Ovectolobus harbatus is yet to be proved. 

 {barbatus^ bearded.) 



Family VI. CAliCHAKlID.E. 

 TYPICAL SHARKS. 



Sharks with two dorsal tins, the first short and high, entirely before 

 the vcntrals, the second comparatively small, opposite the anal; no 

 spines; gill-openings moderate, the last above the base of the pectorals; 

 tail more or less l)ent upward from the base of the caudal Hn; sides of 

 tail not keeled; eyes with nictitating membranes; head not hammer- 

 shaped, the snout longitudinally produced, as usual among sharks. 

 Spiracles small or obsolete. Species oviparous. 



A large family, found in all seas. The species are often closely 

 related and difficult of determination. 



a. Mustelin.e: Teeth flat and paved, without cuspH or ridges; spirat-les present; no 

 pit at root of tail; labial folds well developed. 



b. Teeth very blunt Mvsfrlns, 8. 



%a. Carchariin^e: Teeth more or less compressed, with entire or serrate sharp edges. 

 c. Spiracles present. 

 d. Root of tail without pit. 



e. Teeth rather small, each witli a medium cusp and one or two small lateral 

 cusps on each side. 

 /. Teeth larger, with sharp cusps; snout of moderate length; embryo not 



attached to uterus by a placenta Trintis, 9. 



ee. Teeth larger, with a single cusp, oblique, notclied and coarsely serrated 



on the outer margin Galcux, 10. 



dd. Root of tail without consi^icuous pit above; teeth all coarsely serrate, alike 

 in both jaws, and all with a deep notch on outer margin; caudal fm with 



a double notch ■ Galeocerdo, 11. 



cc. Spiracles obsolete; lower teeth narrower than upper teeth. 



(/. Angle of mouth without groove or with merely a slight depression, 

 which does not extend along either jaw. 

 //. First dorsal fin inserted posteriorly, nearer ventrals than pectorals; 

 embryo not joined to the uterus by a placenta; slender sharks, 



with very strongly serrated teeth Prionace, 12. 



/(/). First dorsal inserted anteriorly, nearer pectorals than ventrala; 

 embryo (so far as known) attached to the uterus by a placenta. 

 /. Teeth all serrate more or less (entire in the very young). 



Carclun'ias, 13. 



gg. Angle of mouth provided with more or less distinct groove, which 



extends along one or both jaws; teeth entire, or very nearly so, 



more or less obliquely j)laced, their points turned away from the 



median line; eml^ryo (so far as known) with ])lacenta. 



Scoliodon, 14. 



