INTRODUCTION. 1 7 



The Hermit Crab (Plate XI.), in his shell surmounted bj 

 the parasitic Anemone ; the Lobster, moving out of his hole, 

 with a forest of green weeds growing upon his shell; the 

 Prawn (Plate XII.), with his splendid livery and delicately- 

 contrived organs, are all fine objects; while their changes 

 and habits, wonderful as they are, can all be observed freely 

 by means of the Aquarium. Even the common Shore Crab, 

 in its earlier stages of growth, is a good acquisition, if care 

 be taken not to give it too much opportunity for displaying 

 its pugnacious qualities. 



Cirrht][)edes as yet have only been represented in marine 

 tanks by the common little Acorn Balanus (Plate XI.), which 

 is common enough, living on the outsides of living and dead 

 shells incrusting pebbles and rocks. It is very interesting 

 to observe the way in which they open their opercular valves 

 to throw out their network of cirrhi to envelope the animal- 

 cules which come within reach. 



Annelida (Plates I., II., IV.) with shelly or pebble-formed 

 tubes and branching ferns of gills, give great variety and 

 beauty to the miniature ocean. 



BcUywdermata, Starfishes (Plate XVII.), Sea Urchins or 

 Echini, and Sea Cucumbers (Plate X.), are very pretty ob- 

 jects, but not generally long-lived in Aquaria. 



c 



