OPHIIOLEPIDAE 



333 



To Koehler's excellent description of this species I have only to add that the upper- 

 most arm spine is a little distant from the two others. The present specimens otherwise 

 agree perfectly with Koehler's description and figures. The largest specimen is 7-5 mm. 

 in diameter of disk, thus exceeding somewhat the largest size hitherto recorded, 6 mm. 

 diameter of disk. 



This species is viviparous but not hermaphrodite. Of two specimens opened one, 

 7 mm. in diameter, proved to be a female, with some ten young embryos in each bursa, 

 all in the same stage of development, with the primary disk plates and the terminals 

 recognizable; the other, 5 mm. in diameter, was a male. In both sexes two to three 

 gonads were found at the interradial side, one to two at the adradial side of the bursa. 



I quite agree with Koehler (op. cit., 1922) that this species does not properly belong 

 to the genus Homalophiiira, to which it was referred by H. L. Clark (Cat. Recent 

 Ophiurans, p. 327), but to the genus Ophiiira, s.str. 



Ophiura flexibilis, var. crassa, n.var. 



St. 170. 23. ii. 27. Off Cape Bowles, Clarence Island, 342 m. i specimen. 



This specimen in general corresponds with O. flexibilis (Koehler), but differs from it 

 in the plates of the disk being smaller and more numerous than in the typical form ; the 



Fig. 46. Ophiura flexibilis, var. crassa, n.var. Part of oral side (a) and dorsal side [b); 



part of arm in side view (c). 



ventral arm-plates are somewhat shorter and broader, and contiguous on the three 

 proximal joints. The arms also are somewhat more robust than in the X.y'piicaX flexibilis. 

 Quite exceptionally there may be five, instead of four, arm spines. 



As the specimen is rather large, 8 mm. diameter of disk, it is quite possible that the 

 differences pointed out are in the main due to age (I have no specimens oi flexibilis of a 

 corresponding size for comparison), and since the differences are rather unimportant, 

 I do not think it desirable to make this single specimen the type of a separate species, 



