158 HAWAIIAN AND OTHER PACIFIC ECHINI. 



fig. 4) are quite common; the valves (PI. 146, fig. 1) are .30-.70 in length, slightly 

 curved and meet only at the tip. The stout tridentate are much larger; the 

 valves (PL 146, fig. 5) are .45-1.00 mm. long and correspondingly heavy. The 

 slender tridentate are remarkable for the compression and depth of the blade, 

 which is of course most striking when the blade is very narrow. The valves 

 (PL 146, figs. 2, 3) vary greatly in length and width; they may be only .30 mm. 

 long with the blade .02-.04 mm. wide but they are usually larger and actually 

 range up to 1.20 mm. long with the blade .10-. 15 mm. wide. The depth of 

 the blade commonly exceeds its width. The triphyllous pedicellariae are 

 much like miniature stout tridentate; the valves (PL 146, fig. 6) are about .15 

 mm. long. 



The most perfect of the specimens is 108 mm. long, 85 mm. wide and 38 

 mm. high. There is no indication of a vertical furrow at the posterior end 

 (" sharp cut immediately above the anal system") such as Mr. Agassiz describes 

 and figures in his Challenger specimen. I think this furrow, however, must 

 have been a case of individual diversity for there is no indication of it in a Chal- 

 lenger cotype in the M. C. Z. collection. It was largely because of the lack 

 of this posterior furrow that Wood-Mason and Alcock considered glauca different 

 from fulva, but its presence is surely not a characteristic feature oifulva. Indeed 

 the form of the test is apparently subject to some diversity for the specimen 

 at hand does not agree with either Agassiz's or Koehler's figure. The position 

 of the apex and the form of the posterior end of the test is as shown in Koehler's 

 figure, but the outline of the anterior end is less evenly convex. One of the 

 dorsal primary spines is unbroken and measures a full 65 mm. 



Station 3684. Six hundred miles north of the Marquesas. Bott. temp.? 

 2463 fms. Gy. yl. glob. oz. 



Station 4647. Between Galapagos Islands and Peru. Bott. temp. 35.4°. 

 2005 fms. Lt. gy. br. glob. oz. 



Station 4709. Between Easter Island and Galapagos Islands. Bott. temp. 

 35.3°. 2035 fms. Glob. oz. 



Station 4742. Between the Paumotus and Acapulco, Mexico. Bott. 

 temp. 34.3°. 2320 fms. Fne. lt. gy. glob. oz. 



1 '.it hy metrical range, 2005-2463 fms. Extremes of temperature, 35.4°- 

 34.3°. 



Nine specimens, eight in fragments. 



