254 HAWAIIAN AND OTHER PACIFIC ECHINI. 



a single pedicellaria of this sort this blunt, marginal serration may have been 

 simply a peculiarity of that one. 



This well-marked species is based on a single specimen in the M. C. Z. col- 

 lection (No. 3201) which was taken by the Challenger at her station 188, 

 west of Torres Strait, 28 fms., mud. It was labeled Lovenia elongata, but whether 

 the other specimens listed in the Challenger Report are conspecific with this 

 specimen or not there is no means at present of knowing. The differences in the 

 form of the test are very striking but the difference in the subanal plastron is 

 probably more important. 



Lovenia cordiformis. 



A. Agassiz, 1872. Bull. M. C. Z., 3, p. 57. 



Plate 161, figs. 8-12. 



Although this species is near enough to elongata to make confusion of the 

 two possible, the narrower and higher test of cordiformis distinguish it easily, 

 as a rule, when specimens are compared side by side. But it is possible that 

 there are specimens of elongata, relatively high and broad, which cannot be 

 separated in this way, from the lower and flatter specimens of cordiformis. 

 Of course very young specimens (PI. 161, figs. 10-12) can scarcely be distin- 

 guished by the shape of the test. The pedicellariae, however, offer some points 

 of difference which probably hold for all ages. The characteristic globiferous 

 pedicellariae on the ventral ambulacra have the valves about .30 nun. long in 

 elongata and the stalk about the same; in cordiformis, the valves are .45-.55 

 mm. long and the stalks about .75; the latter are uniformly fusiform in cordi- 

 formis but in elongata are abruptly tapered at each end. The rostrate pedicel- 

 lariae are very common in cordiformis and have the valves, .40-. 50 mm. long, not 

 greatly curved but rather abruptly so at the tip; the blade is about half the 

 valve; it is distinctly widened at the tip but even at the middle, its width is 

 one sixth to one fifth of its length; in elongata the blade may be much more 

 than half the length of the valve and its width may be not more than one ninth 

 of its own length. The triphyllous and tridentate show no differences of impor- 

 tance. In cordiformis, the triphyllous valves arc about .12-. 15 mm. long and 

 .05-.06 mm. wide; the tridentate are .17-82 mm. long with the blade rather 

 more than half of that; the width of the blade, which in large pedicellariae is 

 more or less compressed, is about one third of its Length or Bomewhal less. The 

 most conspicuous pedicellariae in cordiformis are the niultidentate. These have 





