28 ARKIV FÖR ZOOLOGI. BAND 8. N:0 10. 



Explanation of Plates. 



Plate I. 



Fig. 1. Mola nasus. Vertical section of skin. Microphoto. X 25 

 v. Gieson's mixture. e, epidermis; ce, exteriör layer of 

 corium; ci, interiör layer of corium, pl, plate with spine. 

 The space between the epidermis and corium is caused by 

 preservation. 



» 2. Mola nasus. Vertical section of skin. Photo. Nat. size. 

 The white mäss is the interiör layer of corium. Outside 

 of this: the plates, the exteriör layer of the corium 

 and the epidermis. Inside of the interiör layer of the 

 corium muscles are seen. 



» 3. Mola nasus. Plate with spine, seen from above. 



Plate II. 



Fig. 4. Mola nasus. Vertical section of plate with base of spine. 



»5. » » Horizontal section of spine showing zones of 



growth. van Gieson's mixture. Photo. X 200. 



» 6. Mola nasus. Interiör layer of corium. van Gieson's mix- 

 ture. Photo. X 200. 



Plate III. 



Fig. 7. Lactoplirys trigonus L. View of part of carapace. Photo, (fo- 

 cused for the pigment of the exteriör layer of corium) X 50. 



» 8. Lactophrys trigonus L. View of part of carapace. Interiör 

 surface. Photo. X 50. 



» 9. Lactophrys trigonus L. View of part of carapace. Photo 

 (focused for the fibrillated part of the plate in order to 

 show the alternating dark and light lines and the canal 

 system). X 10. 



» 10. Lactoprys trigonus L. Vertical section of part of a plate 

 (ef. Fig. E). v. Gieson's mixture. Photo. X 60. a, bundles 

 connecting two plates; h, homogeneous part of plate; hb, 

 horizontal bundles crossing each other (= b and c in Fig. E); 

 vb, vertical bundles (= a in Fig. E); la, lamellse. 



