52 Mr. C. T. Regan on the 



Ilab. Atlantic coasts of Europe ; Japan. 



In the British Museum eleven specimens, measuring up to 

 950 mm. in total length. 



The species is very variable, and the fins are larger in the 

 young tlian in the adult. In three specimens from Portugal 

 of about 260 mm. the base of the second dorsal (without tlie 

 spine) varies from | to -^(j of that of the first dorsal (without 

 the spine), which is contained from less than If to more than 

 If times in the distance between the dorsals. I am unable 

 to separate specifically from these a Japanese specimen of 

 380 mm. received as JDeania egJantina. In adult specimens 

 the base of the first dorsal (without the spine) is about -| the 

 interspace between the dorsals. 



3. Gentrophorus rostratus. 



Acanthidinm rostrafum, Garm. Bull. Mus. Comp. Zool. xlvi. 1906, 

 p. 206. 



Uab. Japan. 



4. Gentrophorus dumerili. 



Machephilus dumerili, Jolmson, Proc. Zool. Soc. 1867, p. 713. 

 Centrophorus dumerili, Giintli. Cat. Fish. viii. p. 422 (1870). 

 Centrophorus squamosm, Vaill. ' Tiavailleur ' et ' Talisman ' Poiss. p. 69, 

 pi. iii. fig. 2 (1888). 



Hob. Madeira. 



In the British Museum one specimen, 1000 mm. in total 

 length, type of the species. 



I am unable to recognize any cliaracter in dentition or in 

 structure of the dermal denticles by which this species may 

 be distinguished from G. squamosus. I cannot therefore 

 accept Vailhmt's opinion, based on examination of a head in 

 the Paris Museum, which appears to be ])art of the type 

 specimen of G. squamosus, tliat this species rather than tlie 

 next is the true Gentrophorus squamosus. 



5. Gentrophorus squamosus. 



Sgualus squamosus, Ginelin, Liuu. Syst. Nat. p. 1502 (1788). 

 Centroi^horus squamosus, Miill. & Henle, Plagiost. p. 90, pi. xxxiv. 



(1838) ; Dum^ril, Elasmobr. p. 448 (1865) ; Gliuth. Cat. Fish. viii. 



p. 422 (1870) ; Holt & Calderwood, Trans. R. Dublin Soc. (2) v. 



1895, p. 373, pi. xiii. fig. 1 ; Jensen, Vidd. Medd. 1899, p. 411, 



pi. iii. ; Collett, Rep. Norweg. Fish. ii. p. 19 (1905). 



Hah. North Atlantic and Mediterranean. 

 In the British Museum three specimens, 1120 to 1350 mm. 

 in total length. 



