138 A NEW ZEALAND NATURALIST'S CALENDAR. 



feet on the underside of the body, and ending in a forked 

 tail, which is also often finely plumose. The eye (or closely- 

 approximated pair of eyes) is usually coloured some bright 

 hue, most commonly red, while in some species little bands 

 or splashes of colour red, blue, or yellow set off the 

 delicately-formed little creatures. In some of the hauls 

 made in Tasman Bay the water in the bottles into which 

 the tow-net was washed became almost pink from the 

 abundance of a little copepod with a series of bright red 

 markings in its body. I cannot state exactly where the 

 phosphorescent light comes from, but many kinds are 

 brightly luminous, and this luminosity is probably of some 

 sexual importance. These animals dart about with great 

 rapidity, their jerky motion in the water being due to the 

 rapid and simultaneous sweep with which they move all 

 their fringed feet. Insignificant as they appear individually, 

 they constitute by their very number one of the most 

 important forms of life which occur in the ocean, for they 

 are the chief food of larger animals, while they themselves 

 feed on microscopically small rhizopods, foraminifera, 

 diatoms, and other animal and vegetable organisms. 



Another peculiar type of crustacean life taken in the 

 surface-net is furnished by the larval forms of crabs and 

 crayfishes. Fishermen here occasionally speak of finding 

 or seeing the young of the lobsters which were liberated on 

 the mole at the Heads some years ago, but they are 

 apparently quite ignorant of the fact that the young of all 

 these higher Crustacea pass through many curious metamor- 

 phoses before they assume the adult form. Not only are 

 these larval forms of glass-like transparency, but they are 

 often of most fantastic shape, and are ornamented with most 

 complicated outgrowths of spines, so that they are utterly 

 unlike the mature animals which produced them. It will 

 give some idea of this extraordinary unlikeness when I 

 mention that the earlier workers in this field of natural 

 history constituted a whole family called the Phyllosomidae 

 from their leaf-like appearance with distinct genera and 

 species, out of the metamorphic forms of the common 

 marine crayfishes. 



