3 o2 LOWER FORMS OF MARINE LIFE 



animals ; some affixing themselves to mussels, others to corals or crabs, and a few 

 to the bodies of whales. Of the commoner kinds, the stalked barnacle (Lepas 

 anatifera), which has the body compressed laterally, is furnished with a long 

 naked stalk, upon the extremity of which are carried the several shelly valves. 



Acorn-barnacles (Balanus), which live within tide-range, have no stalk to 

 the shell but resemble the stalked forms in general structure, although the base of 

 the shell is welded into a solid cone resembling a miniature volcano, at the summit 

 of which are the movable valves. These barnacles affix themselves to rocks, piles, 

 snells, or seaweed, but never to coral-reefs. They are widely distributed, their 

 range extending from latitude 74° 18' N. to Cape Horn, although they are 

 rather more abundant in temperate waters than elsewhere. Such of the allied 

 forms as attach themselves to floating objects are frequently modified to suit the 

 special conditions ; the whale-barnacles of the genus Coronula having, for 

 example, flattened crown-shaped shells. 



Cuttles and No group of animals is more abundantly represented in the ocean 



Squids. than that of the shell-fish, or molluscs, and in none is the distribution 

 more dependent on depth and temperature, w T hile in none are different regional 

 marine faunas more clearly differentiated. Of the four main divisions, the one 

 which includes the cuttles and squids is exclusively marine. One of the most 

 familiar in this group is the octopus or kraken (Polypus vulgaris), of the 

 Mediterranean and west European seas, w T here it lurks in rocky clefts or other 

 hiding-places, and feeds voraciously and indiscriminately on all kinds of animal 

 substances. To the same section belongs the paper-nautilus, the females of which 

 exhibit the peculiarity of secreting the well-known delicate shell as a protection 

 for their eggs, this shell being unattached to the body and capable of being dis- 

 carded. Of the four kinds of paper-nautilus, which are found in all the warmer 

 seas, the common Argonauta argo is Mediterranean, while A. tuberculata, distin- 

 guished by the knotted ribs and tubercles on the shell, inhabits the Indian Ocean. 



In a second section of the group, distinguished by the presence of ten, in place 

 of eight, tentacles around the mouth and the horny nature of the internal skeleton, 

 or pen, mention may first be made of the genus Ommastrephes, in which the body 

 is cylindrical and pointed behind, and furnished with two terminal fins. These 

 short-armed gregarious cuttles, which swim very fast and follow shoals of young 

 mackerel, form the principal food of several kinds of dolphins. One of the most 

 abundant species (0. sagittatus) inhabits the Mediterranean and Atlantic, and is 

 largely used as bait in Newfoundland, where it is occasionally eaten as food. 



The giant cuttles (Architeuthis), which belong to the same family, attain a 

 length of from 40 to 50 feet, and are occasionally met with on the coasts of Ireland, 

 Japan, New Zealand, and Newfoundland. The calamaries are also long in shape, 

 but the pen, instead of being narrow with a hollow cone at the hind-end, is 

 broadly lanceolated and pointed in front, with the shaft keeled on the lower side. 

 These calamaries are cosmopolitan in distribution, the best known being perhaps 

 the common squid (Loligo vulgaris), so abundant in the Mediterranean and Atlantic. 

 In these squids the pen is as long as the body, whereas in the allied Sepiola it is 

 but half this length and proportionately narrower. In the Mediterranean and 

 Atlantic the latter group is represented by Rondelet's calamary (Sepiola rondeleti). 



