58 



NATURAL HISTORY OF OUR SHORES 



a set of lodgers, in the way of numbers of young fishes, 

 which make themselves quite at home therein, darting out 

 upon their prey and then back to this peculiar shelter. In 

 some species e.g. Pelagia these pockets are the constant 

 home of a curious little crustacean, one of the Amphipods, 



Hyperia. How these tenants 

 or lodgers avoid the deadly 

 sting cells, and subsequent 

 attention of their hosts, is 

 difficult to guess. 



In the jelly-fish group, 

 forming a division classed 

 as the Siphonophora, are 

 some curious and beautiful 

 organisms. The most abun- 

 dant is a little apple-shaped 

 one, named Cydippe pomi- 

 formis, or Hormophora pomi- 

 formis (Fig. 22). It is about 

 the size of a hazel-nut, with 

 the appearance of glass and 

 the texture of a gooseberry. 

 It has eight bands passing 

 from apex to base, and these 

 bands are crossbanded with 

 rows of cilia, which move 

 almost continuously, with a 

 wavelike movement, causing 



a play of light and iridescence which is extremely beauti- 

 ful, the little creature gleaming with rainbow tints. 



The bands of cilia are under nervous control, for some- 

 times one band, then another, may stop and again break 

 into play. It has two long streamers, which are set with 

 little feathery appendages on all their length, and which 

 appendages can be retracted at will into pockets at its sides. 



Fig. 22. Hormophora pomiformis 

 Natural size 



