On the Pelagic Fauna of our Shores. 137 



Genus Peltastes, Agass., 1838, amended. 

 Syn. Hyposalema, Desor. 



Subgenus GoNiOPiiORUS, Agass., 1838. 



Genus Salenia, Gray, 1 835, amended. 

 Subgenus Heterosalenia, Cott., 1861. 



XVI. — On the Pelagic Fauna of our Shores in its Relation 

 to the Nourishment of the Young Food-Fishes. By Prof. 

 M'iNTOSH, M.D., LL.D., F.R.S., &c.* 



By the term pelagic fauna is meant the inhabitants of the 

 whole body of the water from the surface to the bottom. 

 This immense area, it is well known, varies greatly in depth, 

 viz. from 4655 fathoms (that is upwards of five miles), as 

 sounded by the American exploring-ship ' Tuscarora,' near 

 the Kurile Islands in the North-east Pacific, to a few inches, 

 as on gently sloping saiuly beaches. 



The pelagic fauna of the surface of the ocean has for ages 

 attracted the attention both of voyagers and of scientific men. 

 In the tropical and subtropical regions especially the abun- 

 dance and variety of such animals are remarkable ; yet they are 

 not confined to these warmer areas, certain types, as copepods 

 and pteropods, occurring in such countless multitudes in the 

 arctic seas that they form the food of the right whales. The 

 colder waters, just mentioned, however, do not, as a rule, 

 present the brightly coloured and conspicuous swimmers of 

 the warmer areas, such as Portugaese Men-of-war, Venus's 

 Girdles, the exquisite siphonophores, pelagic annelids (e. g. 

 Alciojxi), and certain types of pteropods and crustaceans. 



In our own seas, even the most superficial observer on the 

 eastern coast must have been struck by the great beauty and 

 abundance of the lilac Aurelice, the deep purple of the young 

 or the rich brown of the adult Oyanece, frequently stranded 

 in multitudes on sandy beaches in autumn ; while in the 

 milder waters off the western shores the greater variety of the 

 purple and reddish medusas (e. g. Pelagia^ j3iquorea, Modeeria, 

 Oceania), the occasional occurrence of such truly oceanic 

 forms as Phi/salia, Velella, and lanthina, the long chains of 

 Salpte, and the crystalline calices and orange polypites of 



* Abstract of Introductory Lecture to the Class of Natural History, 

 University of St. Andrews, November 1-3, 1886. 



