456 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Plate 13. 



Ophiotreta matura. 



Fig. 1. A specimen from station 5506 ; ventral surface. 



2. A specimen from station 5526 ; dorsal surface. 



3. A specimen from station 5339; ventral surface. 



4. A specimen from station 5467 ; ventral surface. 

 5 : A specimen from station 5499 ; ventral surface. 



Plate 14. 



Ophiotreta matura. 



Pig. 1. A specimen from station 5424; dorsal surface. 



2. The same; ventral surface. 



3. A specimen from station 5538 ; ventral surface of an arm. 



4. A specimen from station 5511 ; dorsal surface. 



5. The same ; ventral surface. 



Plate 15. 



Fig. 1. Ophiotreta matura from station 5648 ; a portion of the dorsal surface 

 of the disk. 

 2. Ophiotreta matura from station 5424; a portion of the dorsal surface 

 of the disk. 



3. Ophiotreta matura; a portion of the ventral surface of an arm. 



4. Ophiacantha vorax from station 5606 ; dorsal surface. 



5. The same; ventral surface. 



6. Ophialcaea congesta from station 5219; ventral surface. 



7. The same; dorsal surface. 



Plate 16. 



Fig. 1. Ophiacantha dollasii from station 5399 ; dorsal surface. 



2. The same; ventral surface. 



3. Ophiacantha dollasii from station 5135 ; ventral surface. 



4. Ophiotreta valeneiennesi from station 5306; dorsal surface of an 



arm. 



5. Ophiacantha henigna from station 5592; ventral surface 



6. The same ; dorsal surface. 



7. Ophiacantha duplex from station 5348; dorsal surface 



8. The same; ventral surface. 



Plate 17. 



Fig. 1. Ophiacantha severa from station 5629; dorsal surface. 



2. The same; ventral surface. 



3. Ophiacantha severa from station 5645 ; dorsal surface. 



4. Ophiacantha legata from station 5536; dorsal surface. 



5. The same; ventral surface. 



6. Ophiacantha longidens from station 5153 ; ventral surface. 



7. The same ; dorsal surface. 



Plate 18. 



Fig. 1. Ophiacantha pacata from station 5589 ; dorsal surface. 



2. The same ; a portion of the dorsal surface more magnified. 



3. The same; ventral surface. 



