

THE OPIIIURIDiE. 



169 



Several specimens from Stations 3357, 782 f . ; 3393, 1020 f . ; 3407, 



885 f.^ and 3408, 684 f. 



From Station 3404, 385 f., there is a young specimen of an Ophiacantha 

 3 mm. diameter of disk, which has mnch resembhmce to 0. inconspima 

 (mouth region, ventral plates, tentacle scales), but differs from that species 

 in the knotted arms; the spines of the disk are as Figure 11, b. From 

 0. moniliformis, which it resembles in the knotted arms, it differs in regard 

 to the mouth shield and the ventral plates. It also very much resembles 

 the 0. pmiacvinm Ltk., but differs from that species through its smooth 

 spines. It may be really that species, but it seems too hazardous to assert 

 upon such scanty material that this species lives both in the Atlantic and 

 the Pacific Ocean. 



) 



I 



47. Ophiacantha spinifera n. sp 



Plate XVI. FJS. 9, I'late XVII. Figs. 1-3. 



^ 



Diameter of disk, 9 mm. ; width of arms close to disk, without spines, 

 2 mm. ; length of arms 4-5 times the diameter of the disk. Three rather 

 long conical mouth papilte on each side of the mouth angle, that on the 

 apex not much wider than the rest. Mouth shield about twice as broad as 

 long, with a rounded peak within and without, inner and outer sides re- 

 enteringly curved, side corners rounded. Side mouth shields a little broader 

 within than without, a little curved; they scarcely meet within. 



First ventral plate suiall, with outer edge much rounded, inner side a 

 little concave. The second usually in contact with the first, those beyond 

 widely separated ; they have a very obtuse angle within, outer edge curved, 

 with a feeble re-entering curve in the median hne ; inner and outer laterals 

 almost straight, outer corners rounded, except on the second plate. The 

 inner ones are a little more broad than long, farther out they are equally 

 broad and long. Side arm-plates with spine-ridge rather prominent. 

 Dorsal plates triangular, with outer edge curved, separated, except on the 

 two inner joints. The inner angle is rounded ; they are about equally 



broad and long. 



The disk is covered by stout, 0.6-0.7 mm. long stumps, which end in 

 three-five thorns (Plate XVI. Fig. 9) ; a few stumps sometimes are found on 

 the dorsal side of the first free arm-joint. The outer end of the radial shields 

 is uncovered; they do not form, ridges. The scaling is rather distinct be- 



'a 



