Page:The Zoologist, 4th series, vol 5 (1901).djvu/215

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American Hydroids. Part I. The Plumularidæ. 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 Plumularidæ; three years later his son, Alexander Agassiz, recognized six species; Prof. Allman, in studying the material secured by Pourtalès in the Gulf Stream, enumerated or described 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 Plumularidæ 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 profusion of genera and species." From a study of all the data obtainable, Prof. Nutting inclines to the conclusion that Plumularian 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.