Sharks of the Family Squalidfe. 55 



Leemargus borealis, Mull. & Henle, Plagiost. p. 93 (1841) ; Dumeril, 



Elasmobr. p. 455, pi. v. figs. 1 & 2 (1865) : Giinth. Cat. Fish. viii. 



p. 426 (1870). 

 Somniosus microcephalics, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 



1896, p. 57; Jord. & Fowler, Proc. U.S. Nat. Mus. xxvi. 1903, 



p. 638. 



First dorsal equidistant from the bases of the pectoral and 

 pelvic fins. 



Uab. Arctic seas, southward to Japan, Oregon, Cape Cod, 

 and France. 



In the British Museum three specimens, 1800 to 4500 mm. 

 in total length. 



2. Somniosus rostratus. 



Scymnus rostratus, Risso, Eur. Merid. iii. p. 138, fig. 7 (1826). 

 Leemargus rostratus, Oanestrini, Mem. Accad. Sc. Torin. xxi. 1865, 



p. 364, pi. ii. fig. ; Giinth. Cat. Fish. viii. p. 427 (1870) ; Helbing, 



Nov. Act. Acad. Germ, lxxxii. 1904, p. 335. 



First dorsal nearer to the base of the pectoral than to that 

 of the pelvic fins ; body more elongate than in S. micro- 

 cephalics. 



Uab. Mediterranean. 



In the British Museum one specimen, 800 mm. in total 

 length. 



11. ISISTIUS. 

 Isistius, Gill, Proc. Ac. Philad. 1864, p. 264. 



A single species. 



1. Isistius brasiliensis. 



Scymnus brasiliensis, Quoy & Gaim. Voy. 'Uranie,' Zool. p. 198 (1824) ; 



Mull. & Henle, Plagiost. p. 92 (1841) ; Dumeril, Elasmobr. p. 453 



(1865). 

 Isistius brasiliensis, Gill, Proc. Ac. Philad. 1864, p. 264 ; Giinth. Cat. 



Fish. viii. p. 429 (1870) ; Garni. Mem. Mus. Comp. Zool. xxiv. 1899, 



p. 34, pi. i. fig. 1. 

 Leiusferox, Kner, Denkschr. Ak. Wien, xxiv. 1865, p. 10, pi. iv. fig. 2. 



Uab. Tropical and subtropical seas. 



In the British Museum four specimens, 150 to 230 mm. in 

 total length. 



12. EUPKOTOMICRUS. 

 Euprotomicrus, Gill, Proc. Ac. Philad. 1864, p. 264. 



A single species. 



