GILBERT AND STARES — FISHES OF PASTAMA BAT 13 



Family SPHYKNID.E. 

 10. Sphyrna tiburo (Linnaus). 



Reported for the first time from the Pacific Coast of America by the Hopkins 

 Mazatlan Expedition (Jordan, 1895 b, p. 383), which secured a single specimen. 

 Although overlooked by previous observers, the species seems to be not rare 

 at Panama. 



Three specimens were preserved, each about 50 cm. long. A number of 

 larger specimens were seen, from one of which were obtained a number of fully 

 develoj^ed embryos. These measure about 20 cm. in length, and exhibit perfectly 

 the reniform shape of the head characteristic of this species. The groove forward 

 from the nostrils is better developed in the embryos than in older individuals, being 

 considerably more prominent even than in specimens of S. tudes, 60 cm. long. Tn 

 examples of S. tihuro, 60 cm. long, the prenasal groove is but little less distinct than in 

 Iks', tudi's of the same size. In the Panama specimens of S. tiburo there is a more 

 decided fold at the angle of the mouth. In S. tiburo the head is both longer antero- 

 posteriorly and wider than in S. tudes, the greater length being in large part due to 

 the greater convexity in the curve of the anterior profile. Thus in *S'. tiburo a line 

 joining inner angle of nostrils cuts off the anterior | of the snout; in S. tudes, 

 the anterior | only. The angle between anterior and lateral margins of head is 

 more obtuse in S. tiburo, owing to this increased convexity of the anterior profile. 

 The angle is as distinct, however, as in S. tudes, and the current statement con- 

 cerning S. tiburo, "anterior and lateral margins of head confluent into a semi- 

 circle," is by no means justified. 



II. Sphyrna tudes (Guvier). 



In common with other species of "Hammer-heads," *S'. tudes is frequently 

 brought into the Panama market. It is undoubtedly abundant along the entire 

 Pacific coast of Mexico and Central America. Several specimens were secured. 



12. Sphyrna zygaena {Linnaus). 



Still more abundant than the preceding species, appearing in the market 

 almost daily. Several sjieciraens were obtained. 



Family SQUALID^E. 



13. Squalus sucklii {Girurd). 



Jordan and Everraann (1896, p. 54) suggest that a single species of Sgualus 

 may be found to extend from the coast of California {S. sucklii) to Chile {" 8. fernan- 

 dinus"). In that case, it would be to this species we should assign the Panama 

 record given by Giinther (1868, p. 396). 



( 3 ) March 2, 1903. 



