: 



162 



THE OPHIUEID^. 



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margin there are some more conspicuous plates. The radial shields are half 

 as long as the radius of the disk^ wholly separated by a few rather large 

 scales; the adradial edge almost straight, the abradial curved; inner end 

 more or less pointed, outer end rounded. Outside the radial shields there 

 may be a very small, narrow scale (not in the figure). Under side of the 

 disk covered with scales, much smaller than those on the dorsal side. The 

 genital scale distinct in most of the length; it appears to be divided after 

 the length, but in the single specimen we could not make that clear without 

 injuring it. (Seen on the left side in Figure 8.) The margin of the disk 



convex, the edge rather sharp. 



Three equal, tapering arm-spines, not quite as long as an arm-joint (they 

 are rather too pointed in the figures). One small tentacle scale at the inner 

 corner of the pore (in Lyman's specimen on the lateral side of the ventral 

 plate) ; the first pair of pores without tentacle scale (not in Lyman's figure). 



Color in alcohol : white. 



41- OpMonereis anmilata Lym. 



Plate XIII. Fig. 11. 



Lyman: lllust. Catalogue Mus. Comp. Zool, No.. I. p. 143. 



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Challenger Ophiuroidca, p. 1G2. 



Of this species there are two fine specimens from Panama. In Figures 

 10, 11, is shown a view of the dorsal side of the arm of this species, and of 

 0. reticulata Ltk, The inner and outer edge of the dorsal plate is a little 

 wider in the latter species, which seems to be the sole difierence between 

 these two species, besides the coloring of the disk. At any rate, they are 

 very closely related, perhaps identical. 



From Station 3405, 53 f., there is a single arm of a large OpJdoncreis 

 (Plate XIII. Fig. 12), whose very wide dorsal plates and very small supple- 

 mentary plates seem to indicate a new species. It is finely colored : along 

 the dorsal median fine there are some small, irregular, dark brown spots; at 

 the margin there is a large dark brown spot on two joints, then two joints 

 without dark color, and so forth, regularly alternating. There are three 

 arm-spines ; the ventral side of the arm as usually in OpMonereis. 







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