228 HAWAIIAN AND OTHER PACIFIC ECHINI. 



interambulacra 1 and 4, where there are about 10 in each. There are no large 

 tubercles at all in interambulacrum 5. Just outside the large tubercles of 

 interambulacra 1 and 4 there is a very narrow but indubitable fasciolar band, 

 which extends across the whole interambulacrum. This indication of a peri- 

 petalous fasciole is also present in the smaller specimen where it even extends 

 across interambulacrum 5. The posterior end of the test is so badly damaged 

 in the larger specimens that both periproct and subanal plastron are gone. 

 In the smaller specimen, the periproct is close to the upper margin of the nearly 

 vertical end of the test and is distinctly wider than high. The subanal plastron 

 is rounded triangular, nearly as long as wide, and four ambulacral plates, on 

 each side (with three large tube-feet) enter into its composition. The subanal 

 fasciole is very well marked. The peristome is flush with the test in both speci- 

 mens; in the larger, it is about 5 mm. long by 6 mm. wide. The labrum is 

 about 10 mm. long and 2-2^ mm. wide; it is in contact with two and a half 

 ambulacral plates on each side. The posterior ambulacra (I and V) ventrally 

 are each 9 mm. wide and except for a few pedicellariae are perfectly bare. The 

 sternum, as near as I can estimate, was about 16 or 17 mm. long by 9 or 10 mm. 

 wide, and was closely covered with primary spines. Color of test and spines 

 (dry), dirty whitish. 



The test was covered with a fairly smooth and dense coat of slender spines 

 about 2 mm. long, but the larger primary spines are 5-10 mm. in length. Pedi- 

 cellariae are abundant and varied, especially a sort of short, stout rostrate, 

 the valves of which (PL 146, fig. 14) range from .50-.85 mm. in length and termi- 

 nate in a conspicuous tooth. Much smaller rostrate pedicellariae. with narrow 

 curved valves as usual, .20-. 35 mm. long, are also present but are not common. 

 Ophicephalous pedicellariae, with valves about .25 mm. long, (besides the 

 loop, .04-08 mm.) are abundant, especially on the ventral ambulacra. There 

 are also a few slender tridentate pedicellariae with valves nearly a millimeter 

 long, the blade .05-.06 mm. wide for two thirds of its length, and abruptly 

 expanding near tip to nearly twice that. A few triphyllous pedicellariae with 

 short, wide valves about .08 mm. long, were also found. 



The two specimens on which this species is based wore supposed to be a 

 new Maretia until careful examination revealed the presence of a poriprt:ilous 

 fasciole. This is, to be sure, very incomplete but in Qymnopatogua pulchelbu, 

 to which micropctalus is most nearly related, young specimens, even until over 

 50 mm. long have the fasciole almost exactly as it is in these specimens. "While 

 these specimens are therefore probably young, the appearance of the genital 



