THE DISCOBOLI. 



CYCLOPTERIDiE, LIPAROPSID^, AND LIPARIDIDiE. 



Though there are several of the more rare Discoboli unrepresented in 

 the Museum's collections, it possesses so many duplicates of certain species, 

 in addition to rare or undescribed types of others, that, because of the 

 imcertainty and confusion existing in the literature as to the validity of spe- 

 cies and genera or their affinities, the facilities here provided for a study 

 of the group are in themselves sufficient inducements for the undertaking. 

 But, besides these, many of the drawings now published had been made 

 long ago, by Mr. Roetter, to illustrate a projected work for the institution 

 to have been written by Prof. F. "W. Putnam. At the instance of the 

 Director of the Museum of Comparative Zoology, this paper has been pre- 

 pared to utilize those drawings, and to make the work the more complete 

 he kindly permits the use of a number of drawings from his own work 

 on the Young Stages of Osseous Fishes. Excepting the outline sketches, 

 the remainder of the illustrations are by the pencil of Mr. J. H. Blake, from 

 specimens herein described. The notes made by Professor Putnam for his 

 intended work were published by him, under the title " Notes on Liparis 

 and Cyclopterus," in the Proceedings of the American Association for the 

 Advancement of Science, Vol. XXII., page 337, 1874. 



IN GENERAL. 



The species belonging to this group are provided with a disk, the trans- 

 formed ventral fins surrounded by a marginal fold of the skin, below the 

 anterior portion of the body, for the purpose of attaching themselves to 

 rocks or other objects to prevent being dashed about by the waves or 

 the currents. This adhesive apparatus is usually spoken of as the sucking 



