378 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



The fishes are the most omnivorous of all sea creatures, some kind 

 or other eating every sort of oceanic creature, and every other prod- 

 uct of the sea. 



Jellyfishes are sometimes of enormous size, ranking with the larg- 

 est of sea animals. At Nahant, Mass., Prof. Louis Agassiz measured 

 one in which the bell was 7y 2 feet across and the tentacles more than 

 120 feet in length ; this was one of those reddish ones frequently seen 

 on the New England coast in the late summer. 



On and above the surface of the sea, especially in the cooler regions 

 where life is most abundant, live great numbers of birds which are 

 truly oceanic and never visit land except to nest. These are mostly 

 of the tube-nosed tribe, albatrosses, shearwaters, petrels, diving pet- 

 rels, etc., and some at least are familiar to everyone who has ever 

 been anywhere at sea. Where ocean life is especially abundant there 

 are multitudes of auks, puffins, inurres, etc., in the northern regions, 

 and of penguins in the southern. Some terns are almost pelagic in 

 habit, like the noddy and the black-backed, and I have seen tropic 

 birds hundreds of miles from land both in the Atlantic and in the 

 Pacific. 



These birds feed chiefly upon small crustaceans, since these are 

 offered most abundantly. The albatrosses and similar large sea birds, 

 however, eat mostly squid which they catch at night, and the other 

 larger birds eat squid and fish when they can get them, especially 

 the terns and tropic birds. But nearly all these birds will eat any sea 

 animal of suitable size, or if divided or divisible into fragments of 

 suitable size, and the floating carcass of a giant squid or whale affords 

 a feast for thousands of them. 



The only oceanic insect is a little water strider, related to the water 

 striders of our ponds, which picks the small crustaceans from the 

 sea and sucks their juices. Though small and inconspicuous, they 

 are not rare, and I have collected many of them both in the China 

 Sea and in the Caribbean. 



But as yet the story of pelagic life is only half complete. The 

 crustaceans for the most part are the intermediates through which 

 the organic material synthesized by the minute plants is made avail- 

 able for the use of the oceanic animals. Each of the larger oceanic 

 animals represents in itself an important reservoir of food for other 

 animals. Besides the predaceous types, there are many creatures, 

 especially crustaceans, that live within the stomachs of other animals, 

 eating the food they swallow, and within the filter of the salps con- 

 suming the minute organisms they are concentrating for themselves. 

 And in addition there are bizarre misshapen forms of very numerous 

 sorts which live within the bodies of practically all the larger crusta- 

 ceans, feasting on their j^ces, with sometimes others living in the 



