312 RECENT OPHIURANS. 



Bay of Bengal) while nietabula occurs only off the southeastern United States, 

 among the West Indies and along the northeastern coast of South America. 

 No allied form is known in the eastern or southern Atlantic nor in the Pacific, 

 and the geographical gap between sculptilis and metabula is therefore enormous. 



1141. A. OBTECTA (Lutken and Mortensen). 



Ophioglypha ohtecta Lutken and Mortensen, 1899. Mem. M. C. Z., 23, p. 119, pi. 2, f. 7-9. 

 Amphiophiura obtecta Matsumoto, 1915. Proc. Acad. nat. sci. Phil., 67, p. 78. 



1 coTYPE. Off the Galapagos Islands, 1360 fms. 



1142. A. OEDIGNATHA, sp. nov. (oKiTxASos, swollen-jawed). Plate 17, f. 10-12. 



Disk 9 mm. in diameter; arms about 18 mm. long. Very similar to A. con- 

 vexa Lyman and A. coronata Koehler but readily distinguished from either by the 

 following combination of characters. Disk covered by the central plate, 5 

 primary radials, 5 primary interradials and the 5 pairs of radial shields, with 

 several small plates visible at the interradial margin ; the central and 5 primary 

 radial plates do not form any more conspicuous rosette than in convexa and there- 

 fore the disk is quite different from that of coronata; the radial shields are about 

 equal to the primary interradial plates, instead of being much larger as in convexa 

 or much smaller, as in coronata. The proportions and arrangement of the genital 

 scales, first upper arm-plate, and arm-comb are as in coronata, and hence entirely 

 different from those of convexa; but the lower arm-papillae are flat and squarish 

 and not slender as in coronata. The under arm-plates, oral shields, adoral plates 

 and oral plates are all much swollen and finely tuberculous or shagreen-like ; in 

 coronata this is also more or less true but the oral plates are least so and may be 

 depressed and smooth, whereas in oedignatha they are relatively the most swollen 

 (hence the name) and the least smooth. Oral papillae, much reduced especially 

 distally where they may be quite wanting. 



Holotype (M. C. Z. 752) and 3 paeatypes (M. C. Z. 753, 758, 764). Off 

 St. Kitts, 208-270 fms. Off Martinique, 472 fms. 



The specimens from St. Kitts were labeled by Mr. Lyman: "Ophioglypha 

 convexa. Intermediate! Only differs from convexa in finer arm comb papillae 

 and in more interbrachial scales on disk margin." The specimen from Marti- 

 nique is labeled: "Ophioglypha variabilis." The arm-comb, large genital scales, 

 first upper arm-plate, lower arm-plates, oral shields and mouth-parts are all 

 unlike those of convexa and preclude referring these specimens to that species. 

 They approach more nearly to coronata but I beUeve the differences in the disk 

 covering and the mouth-parts forbid reference to that species. It is therefore 



