248 BULLETIN OF THE 



verse oval. The surface of the arm, as well as that of the disk, is microscopically- 

 tuberculous. Disk covered above by swollen plates, of which there is a cen- 

 tral rosette of eleven ; one ten-sided in the midst, and surrounding it ten 

 hexagonal, with unequal sides, whereof the brachial plates are the largest ; 

 all are continued, by single rows of small plates, to margin of disk. Below, 

 the interbrachial space is occupied by large, thick genital plates, and by two 

 others placed on the median line. Radial shields large, longer than broad, 

 wider without than within, where they join the central rosette ; length to 

 breadth, 1.2 : .9. Genital openings narrow and very short, beginning at outer 

 corner of radial shield. Three very small peg-like arm-spines, less than half 

 as long as a joint. Second pair of mouth-tentacles issuing from pores just in- 

 side the side mouth-shields ; first pair of arm-tentacles with three minute, lip- 

 like scales ; those beyond usually with only one small scale. Color in alcohol, 

 pale gray. 



"Challenger" Expedition, Station 173, 310 fathoms, 1 specimen. 



Ophiomastus secundus Ltm. 



Station 136, Santa Cruz, 508 fathoms. Station 149, St. Kitts, 60-150 fath- 

 oms. Station 163, Guadeloupe, 769 fathoms. Station 179, Dominica, 824 

 fathoms. Station 180, Dominica, 982 fathoms. Station 182, Dominica, 1131 

 fathoms. Station 185, Dominica, 333 fathoms. Station 196, Martinique, 

 1030 fathoms. Station 205, Martinique, 334 fathoms. Station 211, Marti- 

 nique, 357 fathoms. Station 230, St. Vincent, 464 fathoms. Station 288, 

 Barbados, 399 fathoms. Station 325, 33° 35' 20" N., 76° W., 647 fathoms. 

 Station 326, 33° 42' 15" N., 76° 0' 50" W., 464 fathoms. Station 329, 34° 39' 

 40" N., 75° 14' 40" W., 603 fathoms. 



Ophiophyllum petilum ? Ltm. 

 Bull. M. C. Z., V. 7, p. 130, PI. VII. Figs. 179-181. 

 Plate IV. Figs. 62-54. 



The single specimen brought up from 542 fathoms at Station 190, near 

 Dominica, differed from the type in having, near the base of the arm, a small, 

 peg-like, additional arm-spine, standing just above the peculiar flat, curved, 

 translucent spine, which seems like a continuation of the free plates which 

 border the disk. Also there were not so many plates in the lower brachial 

 space. All the disk plates were thin and more or less diaphanous, so that 

 their outlines were hard to make out unless the specimen was partly dried. 

 These differences may be constant and specific ; but I prefer to leave them in 

 doubt because only one adult specimen of the typical O. petilum was brought 

 back by the " Challenger." 



There is a certain re.semblance in some parts of the Ophiuran fauna of the 

 Fijis from depths of 200 to 600 fathoms to that of the West Indies at the 



