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BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



figure, the second segment is already mucli longer than broad. In fact it is not more 

 than half again as long as broad on any of the remaining cirrus bases. The third seg- 

 ment, however, is markedly longer than the preceding one, about four times as long 

 as its median width and the fourth and fifth segments are up to six times as long as 

 their median widths. Carpenter described the following segments as slowly decreasing 

 in length, the penultimate being scarcely longer than wide and bearing a small opposing 

 spine. Probably his figure is reasonably correct except that a basal segment has been 

 omitted from each cirrus (pi. 33, fig. 1). 



The radials arc not overlaid by the ccntrodorsal with which they form a continuous 

 curve or wide angle since they are aligned at no more than 45° to the dorsoventral a.xis 

 and so are not so much foreshortened in side \dew as are the radials of Bathymetra 

 carpenteri. They are about twice as broad as long in the median line with the distal 

 border strongly concave and the interradial angles produced so as entirely to separate 

 the bases of the IBri. These are about the same size as the radials and are deeply in- 

 cised by the IBrj. The latter are arrowhead-shaped with the apex directed proximally, 

 the proximal sides are slightly convex and the shorter distal sides very concave. The 

 distal angle is truncated. In the larger of the two specimens the axillary is as broad 

 as long, in the smaller one it is relatively longer. 



The arms of the larger specimen were probably about 25 mm. long. From the 

 proximal edge of the IBri to the second syzygy is 7.5 mm. and in the smaller specimen 

 6.5 mm.; the widths at the first syzygy are respectively 0.8 and 0.6 mm. 



Figure 43. — Bathymetra abyssicola 

 (P. H. Carpenter), a, larger and 

 h, smaller syntypes. 



