ARKIV FÖR ZOOLOGI. 



BAND 8. N:o 10. 



(From the Zoological Institute, Lund.) 



Studies on the Plectognaths. 



3. The Integument. 



By 



NILS ROSÉN. 



With 5 Plates and 8 Figures in the Text. 



Communicated February 12th 1913 by E. Lönnberg and O. Carlgren. 



Our knowledge of the integument of the Plectognaths has 

 hitherto been limited almost to the integumental ossifications, 

 which on account of their value as systematical characters 

 have been rather well described as regards the shape. Espe- 

 cially Hertwig has given a detailed account thereof. Other 

 works have been written by Williamson, Holland and 

 others. The peculiar integument of Mola is rather well de- 

 scribed in part by Turner. This inquiry is not intended to 

 be a monograph of the integument. I wish only to point 

 out the chief characters of the different groups, and try to 

 find relation between them. 



Molidae. 



Every one who has an opportunity of examining a Mola 

 must at once be struck by the enormous development of the 

 skin. Beneath the thin layer containing numbers of close]y 

 set small tubercles there is a very thick mäss of a white 

 colour. This låter layer is in some parts several centimetres 



Arkiv för Zoologi. Band 8. N:o 10. 1 



