AEKIV FÖR ZOOLOGI. 



BAND 10. X:o 8. 



(From the Zoological Institute, Lund.) 



Studies on the Plectognatlis. 



5. The Skeletoii. 



By 



NILS ROSÉN. 



With 2 Plates and 5 Figures in the text. 

 Communicated November 24th 1915 bv Hj. Théel and E. Lönnberg. 



In the middle of the eighteenth century the skeleton of 

 the Plectognaths was the object of several researches. The 

 skeleton of Mola was studied by Wellenbergh, Goodsir 

 and Cleland, while Hollard described the other forms. The 

 accounts given bv these authors were of course exclusivelv 

 descriptive. Though very detailed and carefully roade, they 

 nevertheless contain several mistakes. The skull of the Mola 

 was låter on examined by Steenstrup and Lutken. A study 

 from a more modern point of view was made by Supino 

 (1905), who has published a paper about the skull of Mola 

 and Balistes. Several years before (1884) Klein had published 

 a few remarks on the structure of the skull of the Plec- 

 tognaths, except Mola. Regan tried to classify the group 

 with regard to the skeleton (1902); but his contribution does 

 not seem to me to have increased our knowledge either of 

 the skeleton or of the phylogeny of the group. The verte- 

 brae and the skeleton of the fins have recently been the 

 especial object of Thilo's studies. This author has shown the 

 relation between the structure of these skeleton-elements 

 and the inflating power which several of the Plectognaths 



Arkiv för zoologi. Band 10. X:o S. 1 



