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NOTICES OF NEW BOOKS. 



American Hydroids. Part I. The Plumularida. By Charles 

 Cleveland Nutting. Washington : Government Printing 

 Office. 



This is the first part of a folio publication devoted to these 

 lowly but most interesting forms of animal life. It appears that 

 the great concourse of Plumularian life in American waters was 

 almost unknown to the earlier workers who studied the group. 

 In 1862 the elder Agassiz, in his ' Contributions to the Natural 

 History of the United States,' included only three species of 

 Plumularidce ; three years later his son, Alexander Agassiz, 

 recognized six species ; Prof. Allman, in studying the material 

 secured by Pourtales in the Gulf Stream, enumerated or de- 

 scribed no fewer than twenty-six species; and, irrespective of 

 the contributions of other workers, " at the time of the inception 

 of the present work, it is doubtful if more than fifty species of 

 Plumularidce were known to occur in American waters." Prof. 

 Nutting gives descriptions and figures of some one hundred 

 and twenty-one species, and remarks : — " It is now evident that 

 the West Indian region is the richest in Plumularian life of any 

 area of equal size in the world. Not even the Australian region, 

 hitherto regarded as by far the most prolific in these exceedingly 

 graceful organisms, can equal our own southern waters in pro- 

 fusion of genera and species." From a study of all the data 

 obtainable, Prof. Nutting inclines to the conclusion that Plumu- 

 larian life increases in species down to a depth of 500 fathoms. 

 Below that depth the data are insufficient to warrant any 

 deductions. This publication is embellished with thirty-four 

 excellent plates, and again attests the excellent and exhaustive 

 manner in which zoology is fostered in the United States of 

 America. 



