100 



The Irish Naturalist, 



June, 



which retains certain archaic characters found only in the 

 remains of fishes from older geological deposits. It is essen- 

 tially a Mediterranean species. It may be extending its 

 range northward, or the incursion into the Atlantic of 

 this voracious fish may be only in the nature of a temporary 

 raid. The snout is rounded, the eyes large, and there are 

 six gill slits at the side of the head instead of the usual five. 

 It grows to a length of about 30 feet, and was once recorded 

 from Scotland and several times from the south of England. 



III. — Centrophorus and Scymnodox — Two Deep-Sea 

 Genera of Sharks in Irish Waters. 



The genus Centrophorus includes small sharks 

 allied to the Piked Dog-fish, and was first recorded 

 from the Britannic area by Holt and Calderwood 

 in 1895.^ These peculiarly deep-sea sharks had pre- 

 viously only been known from the coast of Portugal 

 and Japan. A regular deep-sea shark fishery exists in 

 Portugal, the skin being used for polishing wood. The 

 species recorded {Centrophorus squamosus) was taken on 

 a long hne at a depth of 250 fathoms, off the coast of Mayo. 

 Some years later Mr. Holt secured a second specimen 

 near the Bull Rock in Kerry in no fathoms of water, wiiich 

 is now in our National Museum ; while no less than nine 

 were taken by Dr. Schmidt, of Copenhagen, on a long line 

 off the west coast of Ireland. I am now informed by Prof. 

 Jensen, of Copenhagen, that Dr. Schmidt secured also a 

 single specimen of Centrophorus calceus off the west coast 

 of Ireland. These species had previously been known 

 from the seas of Portugal. A specimen of the allied genus 

 Scymnodon was secured by Mr. Holt, off the Tearaght 

 Rock, in between 215-515 fathoms of water, and identified 

 by him as Scymnodon ringens, Bocage, which, like Centro- 

 phorus, was known from the seas of Portugal. 



1 Holt and Calderwood, Survey of Fishing-grounds, W. Coast of 

 Ireland, 1890-91, Trans. R.D.S. {2), vol. v., 1895. 



