OPHIURANS OF UNITED STATES NATIONAL MUSEUM. 17 



plate it is wider than on the following ones, and it forms an almost rounded prom- 

 inence which does not reach the proximal margin. It is on the three succeeding 

 plates that the median protuberance reaches its full development; it is thin, sharp, 

 and extends over the whole length of the plate. On the fifth plate it is less 

 developed, lower, narrower, and does not always^ reach the proximal margin of 

 the plate. Finally, the sixth plate sometimes shows, in the middle of its distal 

 side, a small conical tubercle. The succeeding plates rapidly become narrower 

 and are longer than wide, and at the same time their proximal angle becomes 

 sharper; they are separated from the ninth or tenth upward. 



The upper brachial plates, the form of which has not been indicated by Lyman, 

 are rectangular, and first they are wider than long with a narrow proximal side, 

 a wide and convex distal side, and diverging lateral sides; they afterwards become 

 as long as wide and finally longer than wide. 



0. devoid had not yet been met with except in the southern regions of the 

 Indian Ocean, and a single specimen only was known; the discovery of that species 

 in the Atlantic is, consequently, very interesting. 



OPHIOGLYPHA FALCIFERA Lyman. 



See for bibliography: 



Ophioglyphafalcifera LYMAN (82), p. 42. 



Albatross station 2659. May 3, 1886. Lat. 28 32' N.; long. 78 42' W.; 

 509 fathoms; br. for.; temp. 45.2 F. One little specimen. 



OPHIOGLYPHA FASCICULATA Lyman. 



Ophioglypha fasciculate LYMAN (83), p. 237, pi. 3, figs. 22-24. 

 Ophioglypha fasciculata H. L. CLARK (08), p. 296. 



Albatross station 2358. Jan. 1, 1885. Lat. 20 19' N.; long. 87 03' 30" W.; 

 222 fathoms; fne. wh. co. One specimen. 



Albatross station 2666. May 5, 1886. Lat. 30 47' 30" N.; long. 79 49' W.; 

 270 fathoms; gy. s.; temp. 48.3 F. Three specimens. 



In the specimen from station 2358 the diameter reaches 14 mm.; the others 

 are smaller, their diameters varying between 7 and 10 mm. 



I think I can refer these ophiurans to 0, fasciculata, for they entirely conform 

 to Lyman's description excepting as regards the number of brachial spines; 

 instead of four, as stated by Lyman, I observe but three, the upper one being remote 

 from the other two which form a small group located near the ventral edge of the 

 arm. The length of these spines reaches two-thirds of the article. Undoubtedly, 

 the spine which ought to be placed in the interspace is lacking, and this is not due 

 to the age of the individuals since the disks of my specimens have diameters rang- 

 ing from 7 to 14 mm., while the diameter was 13 mm. in Lyman's type. This 

 difference would evidently not justify a specific separation. 



Lyman says, as pointed out by H. L. Clark (08, p. 296), that the lateral brachial 

 plates are not in contact either on the upper or on the under face, but in his drawings 

 these plates are represented as being in contact beyond the sixth under brachial 

 plate. I observe on my own specimens that the under plates are in contact for a 

 length which varies, according to the size, from the seventh to the fifteenth article. 



Lyman's type was caught by the Blake in the waters about Barbados, in a 

 depth of 288 fathoms. 



