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118 



THE OPHIURIDiE. 



The first three ventral plates in contact, those beyond widely separated ; 

 all with outer edge rounded. First ventral plate triangular, almost as large 

 as the next one; second and third with inner end truncated, the rest with 

 an angle within; lateral sides re-enteringly curved. The whole under side 

 of the arm rounded. Side arm-plates long and almost straight, meeting 

 below from the third, above from the second (free) joint. Dorsal plates 

 triangular, with all three sides a little curved. Between the papillae of the 

 arm-comb are seen one or two very small dorsal plates, and one larger with 



inner end truncated. 



The disk is covei^ed with rather large, irregular, overlapping scales, 

 among which the primary plates are not very distinct. Radial shields not 

 much larger than the other scales, meeting broadly without, the one over- 

 lapping the other; inner ends separated by one or two scales. In the 

 interbrachial spaces there are two great scales, which connect the radial 

 shields of each two adjoining arms ; at the margin of the disk there are 

 more small scales. The margin of the disk very high and abrupt, no 

 sharp edge between ventral and dorsal side. The ventral side of the disk 

 covered almost by the mouth shield alone. Genital scale large, growing 

 gradually broader outwards, where it passes to the dorsal side of the arm ; 

 here it makes a conspicuous plate outside the radial shield, bearing the arm- 

 comb. Papilla) along the genital slits short, square, and close set; at the 

 sides of the arm they gradually become long and pointed, and make then a 

 veryAvell developed arm-comb; 8-10 papilla) visible from above. There 

 is a secondary arm-comb, consisting of shorter pointed papilla), inserted on 

 a little supplementary plate at the upper end of first side arm-plate, which 

 reaches the dorsal side of the arm (Plate V. Fig. 3). 



Three, on the first (free) joints four, equal, evenly spaced, rudimentary 

 arm-spines. Tentacle pores large, distinct in the whole length of the arm, 

 as far as can be judged from specimens with broken arms. First pore not 

 opening into the mouth space. Tentacle scales : first pore with two or three 

 on each side ; second and third, with three on each side ; fourth, with two or 

 three on outer, two on inner side ; fifth, with one on each side ; the following 

 with only one scale, on the outer side. 



Color in alcohol : gray. 



Seven almost equally large specimens, from Station 3370, 134 f 



The other specimens differ very little from the one described. Only 



the number of tentacle scales is somewhat variable, there being often 4-5 



papilla) on the inner side of the second to fourth pore. 





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