N. ROSÉN, STUDIES ON THE PLECTOGNATHS. 29 



Plate IT. 



Fig. 11. Spheroides testudineus L. Skiu of the back. Sp. spines; 

 f. longitudinal folds. 



» 12. Spheroides testudineus L. Young specimen. Vertical longi- 

 tudinal section of skin of the lateral side. Boraxearmin, 

 Bismarckbrown and Indigo-carmine. Photo. X 200. ep. 

 epidemis; co, corium; cm, circular muscles; set, subcu- 

 taneous tissue. 



» 13. Spheroides testudineus L. Adult specimen. Vertical longi- 

 tudinal section of skin of the belly. co, corium; cm, cir- 

 cular muscles; hn, longitudinal muscles: set, subcutaneous 

 tissue; ais, air-sac; sp, spine. v. Giesons mixture. X 40. 



» 15. Biodon holacantJius. Skin with spine. Photo. X 3. 



Plate T. 



Fig. 14. Spheroides testudineus L. Vertical section of base of 

 spine. X 10. 

 » 16. Biodon Jiolacanthus. Horizontal section of spine showing 

 zones of growth. 



Tryckt den 21 juli 1913. 



Uppsala 1913. Almqvist & Wiksells Boktryckeri A.-B. 



