656 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxii. 



six transverse irregular broad bands of dark olive brown, the intervals 

 between being- often much spotted with the same color, but sometimes 

 much lighter. The whole integument is also finely dotted with olive 

 greenish to brownish. In most specimens the bands on the back are 

 decidedly greenish and the tubercles are marked by a j^ellowish-green 

 base and a dark brown summit. Ventral surface finely dotted with 

 olive, each pedicel l)eing surrounded by an unmarked area at the base. 

 Length about 100 nmi. 



Localities. — Honolulu, reef (9); Puako Bay, Hawaii (1); Laysan, 

 reef (2). 



The dorsal and ventral surfaces are well differentiated in this form. 

 Just above the edge of the ventral area is a row of fifteen to twenty 

 low tubercles, in some specimens hardly visible, in others easily seen 

 by reason of their darker tips. The two dorsal series are very irregular 

 in some examples, so that in the anterior half of the bod}^ no especial 

 order seem s to be present. The arrangement of pedicels in longitudinal 

 bands is best made out in specimens which have been so hardened that 

 the ventral surface is unwrinkled. The more numerous dots along 

 the spaces between the bands make the latter all the more noticeable. 

 In some examples, however, I find it impossible to distinguish any 

 regular arrangement. 



Calcareous ring of the usual form. Polian vesicle single, about 25 

 to 30 mm. long. Madreporic canal free, single, on right side of 

 mesentery. Cuvierian organs present, forming a relatively very large 

 bunch. 



In this species both tables and buttons (if the peculiar rods may be 

 so classed) are rather incomplete, although numerous so far as indi- 

 viduals are concerned. The disk is usually a subcircular but more or 

 less irregular simple ring, with a fair-sized perforation at the base of 

 each slender spire rod, and frequently supplementary holes between. 

 The edge is usually smooth. Disks vary from 0.03 to 0.05 mm. in 

 diameter; 0.038 to 0.()4») mm. is the average. Spire has one cross 

 beam, is frequently incomplete, and ends in four simple teeth. The 

 crown may have no transverse pieces, in which case the spire is rather 

 rudimentary, or there may be two or three of the teeth connected 

 by transverse pieces (see figures). The rods commonly vary from 

 0.021 to about 0.072 mm. in length, although much larger rods, 

 intermediate in size between the small ones and supporting rods, are 

 present. These rods — or, as Lampert classes them, buttons — are ver}^ 

 irregular. They are smooth and some of the commoner shapes are 

 best seen from the figures. Thesd forms are only a few among a great 

 many variations. The pedicels possess well-developed terminal plates, 

 but in the papillje they are \'erv rudimentary. The pedicels and 

 papillte, in addition to rather long, curved rods with short irregular 

 processes scattered along the sides, have bilateral fenestrated plates, 



