50 Mr. C. T. Regan on the 



Ceyitroscymnus ccelolepis, Goode & Bean, Mem. Mus. Comp. Zool. xxii. 



1896, p. 14, pi. iv. fig. 13 (1896). 

 Centrosci/mnus crypt acanfJms, Kegan, Auu. & Mag. Nat. Hist. (7) xviii. 



190G, p. 4;37. 



Hah. Madeira. 



In the British Museum one specimen, 700 mm. in total 

 length, type of the species. 



5. Centroscymnus ohscurus. 



Ceyitroscymniis ohscurus, Vaill. ' Travailleur ' et ' Talisman ' Poiss. p. Q7, 

 pi. ii. fig. 2 (1888), 



Hah. Coast of Soudan, 1400 to 1435 metre.s. 



6. Centroscynuxus crepidater. 



Centrophorus crepidater, Bocage & Capello, Proc. Zool. Soc. 1864, p. 262, 



fig. 3 ; Gunth. Oat. Fisli. viii. p. 421 (1870). 

 Centrophorus i-ossi, Alcock, Ann. & Mag. Nat. Hist. (7) ii. 1898, p. 143, 



and 111. Zool. ' Investigator/ Fishes, pi. xxvi. fig. 3 (1899). 



Hah. Atlantic and Indian Oceans. 



In the British Museum one specimen, 750 mm, in total 

 length. 



8. Centrophorus. 



Centrophorus, Miill. & Ilenle, Plagiost. p. 88 (1838). 

 Lepidorhinus, Bonap. Nuov. Ann. Sci. Bologna, ii. 1838, p. 207. 

 Machephilus, Johnson, Proc. Zool. Soc. 1867, p. 713. 

 Deania, Jord. & Snyder, Proc. U.S. Nat. Miis. xxv, 1902, p. 80. 



Thirteen species, all found at considerable depths. 



Synopsis of the Species. 



I. Posterior angle of pectoral fin not or but slightly produced, 



A. Eye equidistant from end of snout and last gill-opening ; dermal 



denticles tricuspid. 



1. Dorsal fins subequal or the second the shorter. 

 Pectoral, when laid hack, extending 5 the distance 



from its base to the Tertical from first dorsal 



spine 1 . hystricosus. 



Pectoral, when laid back, extending more than ^ the 

 distance from its base to the vertical from first 

 dorsal spine 2. calceus. 



2. Second dorsal a little longer than the first . 3. i-ostrains. 



B. Eye nearer to end of snout than to last gill-opening. 



1. Dermal denticles leaf-shaped, with serrated edges, each with a 

 strong median keel and sometimes a weaker keel at each 

 lateral edge. 

 Length of base of second dorsal (without the spine) 

 § that of the first (without the spine), which is 

 ^ the interspace between the two 4. dtmierili. 



