146 



BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



outer end. Oral papillae two on a side, one thick and knob-like at 

 apex of jaw, the other long, thick, and spine-like at outer corner of 

 mouth angle; tentacle scale of first oral tentacle pore, long and 



FIG. 58. AMPHIURA ACRYSTATA. a-/, X 5. g-i, X 4. a-c, TYPE, a, FROM ABOVE; 6, FROM BELOW; 



C, SIDE VIEW OF TWO ARM JOINTS NEAR DISK; d, ANOTHER SPECIMEN, FROM ABOVE; C, FROM BELOW; 

 /, SIDE VIEW OF TWO ARM JOINTS NEAR DISK; Q, ANOTHER SPECIMEN, FROM ABOVE; tl , FROM BELOW; 

 /, SIDE VIEW OF THREE ARM JOINTS NEAR DISK. 



spine-like, easily mistaken for an oral papilla. First under arm plate 

 much wider within than distally ; second plate pentagonal ; succeeding 



