46 BULLETIN OF THE 



Station 172, 240 fathoms, 1 specimen. 



This species stands very close to 0. miliaria of the West Indies, and comes 

 from a similar depth. It seems sufficiently distinguished by the arm-spines, 

 which are more numerous by one or two, and more flattened, showing even a 

 feeble tendency to become spatulate. 



OPHIOMYCES Lym. 

 Ophiomyces grandis sp. nov. 



Plate XIV. Figs. 383 - 385. 



Special Marks. — 'Eleven sharp, flat arm-spines, set along the whole upper 

 and side edge of the plate, and growing longer from above down to the ninth. 

 Basal under arm-plates, large and squarish, and bearing three long spatula-like 

 tentacle- scales. 



Description of an Individual (off Tristan d'Acunha). — Diameter of disk 6.5 

 mm. Length of arm about 25 mm. Width of arm near disk 2.2 mm. Four 

 or five broad, flat teeth, with a curved, cutting edge ; the lowest one being 

 much the narrowest. Below these, and still on the jaw-plate, are three spini- 

 form tooth-papillse. Then, from apex of mouth-angle, there radiate, on each 

 side, two rows of long, flattened mouth-papillae, which completely hide the 

 underlying parts ; each row has five or six papillae, of which the innermost one 

 is spiniform, resembling a tooth-papilla ; those beyond, more or less spatula- 

 shaped, grow progressively larger and wider, until the outermost has almost a 

 fan-shape ; all incline more or less downward and outward, so that they overlap, 

 tile fashion. On cutting away the mouth-papillae, a small mputh-shield, of an 

 irregular, short diamond-shape, may be seen, together with small triangular 

 side mouth-shields, which nearjj meet within. Length of mouth-shield to 

 breadth .7 : .7. The jaws are long, narrow, and slender, with very large sockets 

 at their base for the second pair of mouth-tentacles. The first under arm-plate 

 is minute, triangular, and difiicult to distinguish ; the second very narrow, 

 closely soldered with surrounding parts, and with deep re-entering curves on 

 the lateral sides ; the fourth plate is four-sided, about as broad as long, much 

 wider without than within, and with deep re-entering curves on the lateral 

 sides ; length to breadth .6 : ,7. Side arm-plates separated below, meeting 

 narrowly above, not swollen, but clean cut and flaring outward. Upper arm- 

 plates twice and a half as broad as long, shaped like segments of a circle, with 

 a clean curve outward ; near tip of arm they are nearly as long as wide, and 

 form a pointed curve, while the side arm-plates are but slightly flaring and 

 meet above on a line as long as the upper plate. The disk was much torn (as 

 usually is the case), but evidently was covered above and below with fine scales, 

 about 4 in the length of 1 mm., whereof many bore minute, peg-like spines. 

 Eleven arm-spines, increasing rapidly in length from the first to the ninth, 

 then diminishing ; the upper ones are slender, sharp, and little flattened ; the 

 lower ones are broad, flat, sharp, and shaped like a bronze sword ; lengths to 



