184 



BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



Although this species is like discycla in many points, notably the 

 arrangement of the arm spines, it is at once distinguished from that 

 species by the spiny disk, separated radial shields, very small oral 

 shields, and decidedly more " beaded" or "knotted" arms. The 

 large spine at the distal end of the radial shields is a conspicuous fea- 

 ture when fully developed, but it is frequently small and sometimes 



FIG. 84. OPHIOMITRA MICROPHYLAX. x 6. a, FROM ABOVE; b, FROM BELOW; c, SIDE VIEW OF TWO ARM 



JOINTS NEAR DISK. 



appears to be wanting. The very broad, outermost mouth papilla 

 reminds one immediately of the similar papilla in the genus Amphi- 

 pholis. 



OPHIOMITRA MICROPHYLAX, new species. 



Disk 9 mm. in diameter; arms about 60 mm. long. Disk with deep 

 interradial notches, covered with numerous small scales, most of 

 which bear minute thorny stumps; these are most numerous at the 



, signifying guard, in reference to the small size of 



, signifying little, and 

 the tentacle scales. 



