INTRODUCTION. 



In presenting this, my first endeavor, to you, I mnst 

 beg your kind indulgence for a subject till recently but 

 little studied ; if you, my reader, will only make an at- 

 tempt, you will find it a most interesting study. 



It is bound to but a small cahier, although the double 

 volume would not be space enough to make a close and 

 accurate description and explanation of only one single 

 family of these little water-inhabitants. 



It contains myriads of beings as perfectly organized as 

 ourselves ; provided with organs, which, if not in as 

 high a state of development as ours, nevertheless exist, 

 and perform their functions instinctively, even if not 

 guided by the distinguishing characteristic of man. 



Many an hour have I passed with a tumbler of water 

 in one hand and a loop in the other, always finding some 

 new creature which till then had escaped my observa- 

 tion. 



Let us remember L. Agassiz's words v on the genus 

 Coryne, and the same may be said of all the animalcules 

 which occur in the New York Croton water. "In order 

 to obtain a correct idea of this Hydroid, the observer 

 must watch it in its native element, under all the circum- 

 stances and conditions of its natural mode of existence 

 and development." 



This pamphlet is accompanied by a few finely executed 

 drawings, which, with but a few exceptions, are drawn 



