94 BULLETIN 84, UNITED STATES NATIONAL MUSEUM. 



These two species do not seem likely to reach a large size, and the diameter of 

 the disk does not exceed 6 mm. in the examples which I know. 



The question might be asked, as it has been for 0. pentacrinus, whether 0. 

 meridiondlis may not be a young form of a large species, for instance, 0. aculeata, 

 because 0. meridiondlis has, like the latter, the external oral papilla widened; but 

 the above hypothesis can not be upheld. For in 0. mendionalis the upper face of 

 the disk is provided with small spines instead of the short stumps which appear in 

 0. aculeata; the arms are moniliform, the lateral brachial plates, strongly protruding 

 and swollen in their distal part, carry spines which become very long and thin on 

 the dorsal side, a character which is lacking in 0. aculeata. Neither can 0. mend- 

 ionalis be mistaken for a young specimen of 0. bidentata. 



0. composita Koehler, which is met with in the Atlantic Ocean, also recalls 

 0. mendionalis by its widened external oral papilla, but differs from it by the upper 

 face of the disk being covered with short stumps andending in a crown of numerous 

 thin and short spinules which are generally arranged in a regular manner, by its 

 nonmoniliform arms which off er comparatively small dorsal plates which are as long 

 as wide, completely flat and without any trace of bulging; by its under brachial 

 plates which are remarkably widened, and lastly by its brachial spines which 

 always remain shorter, dorsally, than in 0. mendionalis. 



OPHIACANTHA VEPRATICA Lyman. 



Plate 13, fig. 6. 



Ophiacantha vepratica LYMAN (78), p. 137, pi. 10, figs. 245-247. 

 Ophiacanlha vepratica LYMAN (82), p. 182, pi. 13, figs. 7-9. 

 Ophiacantha vepratica LYMAN (83), p. 261. 



Albatross station 2415. Apr. 1, 1885. Lat. 30 44' N.; long. 79 26' W.; 440 

 fathoms; co. crs. s. sh. for.; temp. 45.6 F. Numerous specimens. 



Albatross station 2416. Apr. 1, 1885. Lat. 31 26' N.; long. 79 07' W.; 

 276 fathoms; co. brk. sh.; temp. 53.8 F. Two specimens. 



Albatross station 2625. Oct. 21, 1885. Lat. 32 35' N.; long. 77 30' W.; 

 247 fathoms; gy. s. bk. sp. Several specimens. 



Albatross station 2661. May 4, 1886. Lat. 29 16' 30" N.; long. 79 36' 

 30" W.; 438 fathoms; gy. s. bk. sp.; temp. 45.5 F. Several specimens. 



Albatross station 2663. May 4, 1886. Lat. 29 39' N.; long. 79 49' W.; 421 

 fathoms; br. s.; temp. 42.7 F. Several specimens. 



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. 



Albatross station 2667. May 5, 1886. Lat. 30 53' N.; long. 79 42' 30" W.; 

 273 fathoms; gy. s. bk. sp.; temp. 48.7 F. One specimen. 



Albatross station 2668. May 5, 1886. Lat. 30 58' 30" N.; long. 79 38' 30" 

 W.; 294 fathoms; gy. s. dd. co.; temp. 46.3 F. Several specimens. 



Albatross station 2669. May 5, 1886. Lat. 31 09' N.; long. 79 33' 30" W.; 

 352 fathoms; gy. s. dd. co.; temp. 43.7 F. Six specimens. 



Albatross station 2753. Dec. 4, 1887. Lat. 13 34' N.; long. 61 03' W.; 281 

 fathoms; bk. s.; temp. 48 F. Several specimens. 



The study of the many specimens gathered by the Albatross enables me to 

 complete Lyman's description or perhaps to correct it on some points. 



