88 The Irish Naturalist. April, 



RISSO'S DOLPHIN: 



A CETACEAN NEW TO THE IRISH FAUNA. 



BY PROF. D'ARCY W. THOMPSON, C.B. 



In the beginning of September, 1900, I heard in Galway 

 that a "porpoise" had been cast ashore some little while 

 before at the bathing place of Blackrock, close by the town. 

 I had not time then to go and look for the animal, but at 

 Christmas time I did so and found it. It turned out to be a 

 young specimen, a little over five feet six inches in length, of 

 Grampus griseus, Cuv., Risso's Dolphin or Grampus, the form 

 known as Grampus rissoanus being now generally conjoined 

 with it as one and the same species. This Dolphin is very 

 easily recognised by the entire absence of teeth in the upper 

 jaw, and by the presence of a small number of large ones 

 at the extremity of the lower jaw, which is much swollen to 

 contain them. It is also remarkable for certain very curious 

 striae or scratches that are very generally present on its skin, 

 and which M. Chaves of Ponte Delgada and M. Jules Richard 

 have lately shown to be in all probability the traces of 

 encounters with very large Cuttle-fishes. I looked for but 

 failed to find these markings on this small and by this time 

 much decomposed specimen. The largest specimen of which 

 I have found a record is a male captured in the Mediterranean 

 by the Prince of Monaco, which measured 3.40 metres, or about 

 eleven feet four inches. A cetacean of about this size came 

 ashore near Galway last summer, in July or August, but its 

 carcase was immediately towed out to sea and sunk ; it is 

 very likely indeed that this was a parent of the young 

 Grampus. 



The species is a rare one, though it appears to have an 

 enormously wide distribution throughout the warm and 

 temperate oceans. It has been taken several times in the 

 South of England ; a shoal of six was captured in Shetland 

 in 1889, two were got in the Solway Firth in 1893, and a 

 skull was brought up in a trawl-net off the Isle of Man in 

 1899, but it is new to Ireland. 



The skull and the somewhat imperfect skeleton of the Galway 

 specimen are now in the Museum of University College, 



