Plate 98. 



1-11. Nacopatagus gracilis A. Ag. ; " Hassler " Exp., off 

 Juan Fernandez G5 fms. 



1. Young specimen of 6.5 mm., seen from tlie aotinal side. 



2. Specimen 17 mm. in length, seen from the actinal side. 



3. The same as fig. 2, seen from the abactinal side. 



4. The same as fig. 2, seen in profile facing the left posterior interambulacrura. 



5. Abactinal system and surrounding plates of specimen of 6.5 mm., seen from the 



exterior. 



6. Abactinal system and surrounding plates of specimen 17 mm. in length, seen from the 



interior. 



7. Actinostome of specimen 11.5 mm. in length. 



8. The second plate of the posterior zone of the left posterior ambulacrum of specimen, 6.5 



mm. in length. 



9. The same plate of a specimen 9 mm. in length. 



10. The same plate of a specimen 11 mm. in length. 



11. The same plate of the specimen of fig. 2, 17 mm. in length. 



