PREFACE. 



The Plates which accompany this volume* have now been drawn on 

 stone for more than twelve years. It was the intention of the late Pro- 

 fessor Agassiz to add to them the anatomy of several of our more com- 

 mon species, but the duties connected with the care of the Museum pre- 

 vented him from accomplishing this task. Although during the last twelve 

 years several important papers have been published on the anatomy of 

 Echinoderms which would necessitate a complete re-examination of the 

 anatomy of Starfishes, it has been thought best, since there was no proba- 

 bility of being able to finish within a reasonable time the necessary ana- 

 tomical investigations to complete this volume as originally planned, to 

 publish the Plates as they were left by Professor Agassiz; all that has 

 been added to them is the lettering necessary for their proper explana- 

 tion. However incompletely the subject of Starfishes is thus presented, 

 these Plates cannot fail to be of value not only as illustrations of a 

 number of our American Starfishes, and as showing the systematic value 

 of characters thus far almost completely neglected, but also as determining 

 the homology of several genera not previously figured, the solid parts 

 of which are given in detail. As several European naturalists are at the 

 present moment engaged upon the study of the Starfishes, it appeared 

 judicious to issue these Plates before they became antiquated. 



* They were intended to accompany the text of the fifth volume of the " Contributions to the Natural 

 History of the United States," by L. Agassiz. 



