478 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



FIG. 4. Ophiothrix propinqua: 

 a, tentacle scale. 

 &, first ventral arm spine near the disk. 



c, first ventral arm spine transformed into a hook. 



d, second arm spine. 



e, third arm spine. 



f, fourth arm spine 



g, dorsal spine. 



5. Ophiothrix spinosissima: 



a, lateral arm spine. 

 &, second arm spine. 



c, dorsal spine. 



d, first arm spine transformed into a hook. 



e, tentacle scale. 



6. Ophiothrix purpurea: 



a, spines of the dorsal surface of the disk. 



b, second arm spine. 



c, first arm spine transformed into a hook. 



d, tentacle scale. 



7. Ophiothrix punato limbata: 



a, second and third arm spines. 



6, first arm spine transformed into a hook at several 



c, club spines of the dorsal surface of the disk. 



d, tentacle scale. 



8. Ophiothrix pusilla: 



a, tentacle scale. .:. , 



ft, first ventral arm spine transformed into a hook. 



c, dorsal arm spine. 



d, second, third and fourth arm spines. 



PLATE 102. 



FIG. 1. Ophiothrix striolata: 



a, spines of the dorsal surface of the disk, 

 fo, tentacle scale. 



c, second arm spine. 



d, first arm spine transformed into a hook. 



2. Ophiothrix stelligera: 



a, club spines of the dorsal surface of the disk. 



b, club spines of the dorsal surface of the disk. 



c and d, first ventral arm spine transformed into a hook with three 

 or four branches. 



e, ordinary spines of the dorsal surface of the disk. 



f, bifurcated spines. 



3. Ophiothrix ciliaris: 



a, club spines of the dorsal surface of the disk. 



4. Ophiothrix trilineata: 



a, lateral arm spines. 

 6, second arm spine. 



c, tentacle scale. 



d, spines of the dorsal surface of the disk. 



e, first arm spine transformed into a hook. 



