102 BULLETIN 84, UNITED STATES NATIONAL MUSEUM. 



OPHIACANTHA (OPHIOTRETA) SERTATA (Lyman). 



Ophiomitra sertata Lyman (69), p. 326. 



Ophiomitra sertata Lyman (78), p. 231. 



Ophiacantha sertata Lyman (82), p. 198. 



Ophiacantha sertata Lyman (83), p. 261. 



Ophiotreta sertata Verrill (99), pp. 40 and 54. 



Ophiotreta sertata Verrill (99a), pp. 336, 337, 338, 348. 



Ophiacantha sertata Kcehler (07), p. 321. 



Albatross station 2342. Jan. 19, 1885. Lat. 2.3° 10' 39" N.; long. 82° 20' 

 21" W.; 201 fathoms; co. One specimen. 



Alhatross station 2350. Jan. 20, 1885. Lat. 23° 10' 39" N.; long. 82° 20' 

 21" W.; 213 fathoms; co. Four specimens. 



Albatross station 2655. May 2, 1886. Lat. 27° 22' N.; long. 78° 07' 30" W.; 

 338 fathoms; gy. s.; temp. 47.5° F. One specimen. 



The diameter of the disk ranges between 5 and 8 mm.; the specimens from 

 Station 2350 are in a fairly good state; the others have most of their arms broken 

 near the base. 



Tliis species was placed by Verrill in his subgenus Ophiotreta. The description 

 which Lyman pubUshed in 1869 is very complete and little has been added to it 

 since. In 1907, I pubRshed a drawing of the under face after two specimens from 

 the dredgings of the Blalce wliich were given to the Jardin des Plantes. 



I find again, on the distal side of the mouth shields, the few little spines which 

 were reported by Lyman. The brachial spines are more or less flattened and 

 translucent. Lyman wrote, in 1869, that the spines, amounting to seven, were all 

 rough; in both specimens in the Jardin des Plantes, the spines are provided with 

 fairly minute and dense denticulations. In the specimen from station 2655, these 

 denticulations are a little stronger and, besides, somewhat irregular and unequal; 

 among those from station 2350, the said denticulations are a little more apparent 

 on the largest specimens. The brachial pores of the first pair often carry two scales, 

 as I indicated in 1907. 



The first upper brachial plates are often contiguous at the bases of the arms, 

 chiefly on the somewhat large specimens, then they part. In no specimen are 

 there any granules on the oral plates and the radial sliields are always distinct; 

 both these characters allow 0. sertata to be distinguished from 0. lineolata to which 

 it is closely allied. 



OPHIACANTHA (OPHIOTRETA) VALENCIENNESI Lyman. 



See for bibhography : 

 Koehler (09), p. 188. 



Albatross station 2320. Jan. 17, 1885. Lat. 23° 10' 39" N.; long. 82° IS' 

 48" W.; 130 fathoms; fne. co. Two specimens. 



Albatross station 2321. Jan. 17, 1885. Lat. 23° 10' 54" N.; long. 82° 18' W.; 

 230 fathoms; fne. gy. s. Three specimens. 



Albatross station 2334. Jan. 19, 1885. Lat. 23° 10' 42" N.; long. 82° 18' 

 24" W.; 67 fathoms; wh. co. One specimen. 



