ARKIV FÖR ZOOLOGI. 



BAND 8. N:o 18. 



Studies on the Plectognaths. 



4. The body-muscles. 



By 

 NILS ROSÉN. 



With 5 Plates. 



Communicated April 13d 1913 by Hj. Thkel and E. Lönnberg. 



(From the Zoological Institute, Lund.) 



Although several papers ha ve been written about the 

 body-muscles of the Teleosts, our knowledge of this problem 

 has still remained rather insufficient. The accounts given 

 have all been quite of a descriptive eharacter. No attempts 

 have been made to compare the muscles of different forms 

 with each other or with those of other fishes. This insuffi- 

 cient knowledge has, however, very recently been supplied 

 in a very excellent manner by Maurer. His paper seems to 

 be of the greatest importance for a true comprehension of 

 the bodymuscles. As I intend to use Maurer's terminology 

 in this paper, I think it will be convenient to give a short 

 sketch of his views before entering into a description of the 

 bodymusles of the Plectognaths. 



Maurer distinguishes two parts of the body-muscles, one 

 dorsal and one ventral, separated from each other by a lon- 

 gitudinal lateral septum. Both the dorsal and ventral musc- 

 les consist of myomers. Each myomer shows typically a 

 zigzag-formed superficial surface with the tips of^ the two 

 cones pointing caudally as shown in Fig 1. Maurer calls 

 the different portions of a myomer a (close to the lateral 

 line), 6, c and d. The dorsal muscles have not been suffici- 



Arkiv för zoologi. Band 8. N:o 18. 1 



