XXTV. — Marine Planarians of New England. 

 By a. E. Verbill. 



Part I. — Dench'occela. 



In the following paper I have brought together the scattered 

 notes, descriptions, and sketches of our native marine planarians 

 made by me during more than twenty seasons spent in the study of 

 our marine invertebrates. But as the planarians were not, at any 

 time, a subject of special investigation with me, my observations 

 and descriptions will be found, in some instances, incomplete and un- 

 satisfactory. At the present time other more urgent duties prevent 

 me from making many desirable supplementary investigations of 

 their anatomy by means of prepared sections. Nevertheless, I trust 

 that this article, with the accompanying figures, will prove of some 

 value as an introduction to the study of our native species of this 

 group, which has, hitherto, been very much neglected by American 

 naturalists. 



The unsatisfactory state of what little literature there is in exist- 

 ence relating to our species may be, to a great extent, the cause of 

 this neglect, I have, therefore, endeavored to unravel the synon- 

 ymy, so far as it is possible to do so with the data at hand. 



The drawings, except a few by myself, have all been made under 

 my direct supervision, partly from living individuals and partly 

 from preserved specimens rendered translucent by suitable reagents* 

 and mounted in Canada balsam. Most of those figures (Plates 42 

 and 43), showing details of anatomy, and many of the general 

 figures were drawn by my son, A. H. Verrill. Some of the general 

 figures from life were drawn by J. H. Emerton and others by J. H. 

 Blake for the XJ. S. Fish Commission. f 



As a general rule alcoholic specimens of planarians cannot be 

 identified with any degree of certainty unless rendered translucent 



* In most cases the specimens have been transferred from strong alcohol to a mix- 

 ture of turpentine and carbolic acid (phenol) which renders them more or less trans- 

 lucent ; they are then mounted in balsam. Various staining agents and other reagents 

 have also been used in making these preparations. 



f For the use of the Fish Commission drawings in this place I am indebted to the 

 liberality of the late Commissioner, Professor S. F. Baird, this article having been in 

 preparation before his death. 



Trans. Conn. Acad. Vor,. A^II. 60 Dec, 189'i. 



