OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 463 



Fig. 4. Ophiothrix foveolata from station 5151 ; dorsal surface. 



5. The same ; ventral surface. 



6. Another specimen ; dorsal surface. 



7. A specimen from the Sunda Islands; dorsal surface. 



Plate 48. 



Fig. 1. Ophiothrix vitrea from station 5593; dorsal surface. 



2. A specimen from station 5139 ; dorsal surface. 



3. The entire specimen from station 5593 ; dorsal surface. 



4. The specimen from station 5179; dorsal surface, more magnified. 



5. Ophiothrix infirma from station 5153 ; dorsal surface. 



6. The same ; dorsal surface, more magnified. 



7. The same; ventral surface. 



Plate 49. 

 Ophiothrix crassispina. 



Fig. 1. A specimen from station 5168 ; ventral surface. 



2. Another specimen ; dorsal surface ; diameter of the disk 4 mm. 



3. Another specimen ; dorsal surface ; diameter of the disk 4.5 mm. 



4. 5. Another specimen ; dorsal surface ; diameter of the disk 7.5 mm. 

 6. Another specimen ; diameter of the disk 5.5 mm. 



Plate 50. 



Fig. 1. Ophiothrix crassispina ; magnified portion of the dorsal surface. 



2. Ophiothrix cumulata; dorsal surface with very thick dorsal spines. 



3. The same ; dorsal surface less magnified 



4. The same ; transverse section of a thick spine. 



5. The same ; dorsal surface with dorsal spines not very thick. 



6. The same ; dorsal surface of the disk. 



7. Another specimen; portion of the dorsal surface of the disk. 



8. The same ; portion of the dorsal surface of an arm on which the dorsal 



spines are strongly thickened. 



Plate 51. 

 Ophiothrix cumulata. 



Fig. 1. A specimen with dorsal arm spines not thickened ; dorsal surface. 



2. Another specimen on which the granules of the dorsal surface of the 



disk are more developed ; dorsal surface. 



3. The specimen represented in Fig. 1 ; ventral surface. 



4. Another specimen ; ventral surface. 



5. A specimen with dorsal arm spines not thickened ; portion of the sur- 



face of an arm. 



Plate 52. 



Fig. 1. Ophiothrix cumulata; dorsal surface of a youn^ specimen (diameter 

 of the disk 7 mm.). 



2. The same ; portion of the ventral surface of an arm. 



3. Ophiothrix crassispina; portion of the dorsal surface of an arm of a 



young specimen (diameter of the disk 5 mm.). 



4. A still younger specimen ; portion of the dorsal surface of an arm 



diameter of the disk 4.5 mm.). 



