NORTH PACIFIC OPHIUKANS IN NATIONAL MUSEUM CLARK. 239 





there is no question of their close relationship to 0. bartletti Lyman, 

 and they therefore belong in Verrill's genus OpMopora, which I 

 believe is probably a very natural group. The only important dif- 

 ferences between hartletti and megatreta, which these damaged speci- 

 mens show, is in the shape of the upper arm plates and in the number 

 of arm spines. Possibly perfect specimens will show differences in 

 the disk. 



OPmOLEBES ASAPHES, new species.a 



Disk 9 mm. in diameter; arms about 20 mm. long. Disk more or 

 less completely covered with rough unequal granules or low stumps. 

 Radial shields long, narrow, well separated, partly bare (along the 

 middle) or wholly con- 

 cealed, their position .o'"'^''''^^""'">f 

 more or less clearly indi- "" 

 cated. Upper arm 

 plates rounded, the first 

 two or three wider than 

 long, the others roughly 

 circular; they are well 

 separated from each 

 other, but the side arm 

 plates do not meet be- 

 tween them; in many 

 places, though not nec- 

 essarily on all arms, sup- 

 plementary plates ap- 

 pear between the upper 

 arm plates; when these 

 are not present the 

 space is occupied by 

 uncalcified tissue. In- 

 terbrachial spaces below F'«- ih.-ophiolebes asaphes. x o. a, from above; 6, 



"^ FROM below; f , SIDE VIEW OF TWO ARM JOINTS NEAR DISK. 



covered With scales, upon 



which a few of the rough orranules are borne. Genital slits short 

 and narrow. Oral shield rounded rhombic, very much wider than 

 long. Adoral plates large but poorly defined, wider without than 

 within, where they do not quite meet. Oral papillae three on a sitle, 

 short, blunt. All the mouth parts are more or less covered by a 

 thick skin, which obscures their outlines even when dry. First 

 under arm plate large, wider than long and wider within than dis- 

 tally; second and third plates somewhat pentagonal, with distal side 

 notched, wider than long; succeeding plates somewhat kidney-shaped, 



« 'Aaa(f>^C, eignifying indistinct, in reference to the indistinctness of many of the 

 plates. 



