98 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



by a unique specimen, should not be united with the genus Ophio- 

 medea. The disk is uniformly and completely covered with small 

 imbricated plates, which conceal the radial shields, but which bear 

 neither spines nor granules; there are three external spiniform 

 mouth papillae, and the tentacle pores are furnished at first with 

 four scales, the number rapidly falling to three; these scales are 

 short and spiniform ; one of them is inserted on the under arm plate, 

 and the two others on the side arm plate ; there is thus a very great 

 analogy in structure between Ophiophrura liodisca H. L. Clark and 

 the other species which I assign to the genus Ophiomedea, and I 

 believe that this genus might without inconvenience include all three 

 species. It is interesting to observe the progressive increase in 

 number of the external spiniform mouth papillae ; there is only one 

 in Ophiomedea duplicata, two in O. discrepans, and three in Ophi- 

 ophrura {Ophiomedea) liodisca. 



OPHIOCOPA SINGULARIS, new species. 



Plate 21, figs. 4, 8, 9. 



Localities. — Albatross station 5173; vicinity of Jolo; Jolo Light 

 bearing N. 82° E., 12.51 kilometers (6.75 miles) distant (lat. 6° 

 02' 55" N., long. 120° 53' 00" E.) ; 340 meters (186 fathoms) ; 

 March 5, 1908; Sh., Co. 



One specimen (Cat. No. 41283, U.S.N.M.). 



Albatross station 5348; Point Tabonan bearing S. 89° E., 33.5 

 miles distant (lat. 10° 57' 45" N., long. 118° 38' 15" E.) ; 686 meters 

 (375 fathoms) ; co. S.; December 27, 1908. 



One specimen (Cat. No. 41280, U.S.N.M.). 



Description. — The specimen from station 5348 is in good condition. 

 The diameter of the disk is 8 mm.; the arms are incomplete, but 

 two of them are preserved for almost their entire length and must 

 have been about 25 mm. long; the fifth is broken off at its origin 

 on the disk. The other is in rather poor condition ; the disk is torn 

 into two unequal fragments, one including the greater part with 

 four arms, and the other a fragment with the fifth arm; a rather 

 deep groove divides the dorsal surface into two almost equal halves. 

 The diameter of the disk is 6 mm., and the arms are about 15 mm. 

 long. 



The disk is rounded. The dorsal surface is covered with rather 

 large plates, which are subequal and imbricated and which show 

 a thin transparent border. In the specimen from station 5173 a 

 certain number of these plates bear each a rather large spherical 

 globule with a rugose surface, of which the number varies from one 

 to four or five on each plate and which are not all preserved, though 

 the scar indicating their presence on the surface of the plates may be 



