The classification of the Muriceid.^. 



This group, containing as it does by far the greatest number of species of all the families 

 of Alcyo7iaria, has always offered unusual difficulties to the systematist -, and the great number 

 of new forms in the Siboga collection makes a thorough revision necessary at this time. Any 

 naturalist who has worked with the Gorgonacea will recognize the perplexities that thus confront 

 the writer. 



The aim has been to preserve a conservative course so far as is consistent with scientific 

 accuracy, and a strong effort has been made to retain as many as possible of the established 

 genera, but one new genus (Versluysia) being added. 



But, in many cases, while the names of the established genera have been retained it 

 has been found necessary to modify the definitions to meet the conditions presented under the 

 great increase of our knowledge since the original definitions were proposed. 



In modifying generic definitions the writer has persued the policy of obtaining, wherever 

 possible, accurate descriptions of the type species of each genus, being greatly aided by the 

 work of Kölliker\ who describes the spicules of the types of several of the older genera, the 

 orio-inal descriptions of which are entirely inadequate, indeed useless, for the purposes of the 

 present work. 



With an accurate description of the tj-pe species of a genus at hand, the writer has 

 used in his generic description any character found in the type that, in his opinion, will serve 

 as a good diagnostic character of the genus. Such characters he has often used to the exclusion 

 of the generic characters used in the original descriptions of the genus. Thus it will be seen 

 that he has retained the names of most of the genera, but modified the definitions in many 

 cases; being careful, however, to introduce no character in his modified genera that is not 

 found in the generic types. 



As is almost universally the case, the earlier writers used the most obvious external 

 characters in defining the zoological groups of the Alcyonaria. Hence the form of the colony 

 and shape of the calyces were regarded as of prime importance, while we now know that, 

 except in a comparatively few cases, these features are practically valueless when applied to 

 the genera of the Muriceidce. A little after the middle of the last century the spicules were 

 recognized as of great importance in the writings of two authors who were mainly instrumental 

 in placing the classification of this group on a much more satisfactory basis. Kölliker and 

 Verrill were among the first to examine carefully these curious structures, and they based 

 their generic characters almost exclusively on the form and disposition of the spicules. 



Subsequent writers have fully recognized the importance of such characters; but have not 

 hesitated to avail themselves of others, such as the mode of branching and shape of calyces, in 

 formulating their generic definitions. Wright and Studer, in their masterly report on the Alcyo- 

 naria collected by the Challenger expedition, persued this method with very satisfactory results. 



' KÖLLIKER. Icones Hislologicte. Vol. II, 1885. Special reference is here made to the descriptions of the spicules of the types 

 of Echinogorgia^ Villogorgia and Thesea. 



