650 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxn. 



appear to possess rudimentary terminal plates, but the greater num- 

 ber show no trace of them. The rods in the walls of the papilla? are 

 very few. The deposits in the ventral perisome, in the form of smooth 

 oval grains and unbranched rods, are highly characteristic, and occur 

 in great numbers, forming several layers. The rods are rather more 

 numerous near the bases of the pedicels, which possess well-developed 

 perforated terminal plates, but no supporting rods in the walls. Some- 

 times, however, a few grains are present near the end, and a few rods 

 also. The grains vary consideralily in size, ranging from 0.01 to 0.04 

 mm. in length. The rods do not generally exceed 0.1 mm. in length. 

 Rosettes are not present in the ventral perisome of all the specimens. 

 Theel found them present in examples from the Samoan, Fiji, and 

 other islands of the South Seas. I find them fairly numerous in a 

 medium-sized, dark, syjarsely spotted specimen from Puako Bay, 

 Hawaii, but in larger individuals with spots, from the same locality, 

 they appear to l)e almost if not entirely wanting. 



This species is found in tide pools in the lava rock, especially on the 

 coast of Hawaii. We did not take any on coral reefs. It is one of the 

 commonest and most characteristic invertebrate forms of the shore 

 fauna, and does not take any special pains to hide itself. 



Genus HOLOTHURIA Linnaeus. 



Holotlmrid Linn.kus, Systema Naturfe, 10th ed., 1758. 



The following description of the genus is taken from Theel: 



Tentacles 20, exceptionally more or lesn. Ambulacral appendages, pedicels alone, 

 papilljB alone, or both papilke and pedicels; the i)apillf« placed on the dorsal surface, 

 the pedicels on the ventral. These ventral pedicels are seldom arranged in longitu- 

 dinal series. A single bundle of genital tubes placed on left side of dorsal mesentery. 

 Anus devoid of calcareous teeth, but sometimes stellate. C-shaped deposits absent. 



KEY TO HAWAIIAN SPECIES OF HOLOTHURIA. 



a. Deposits simple or l)ranched rods, the branches being sometimes united, the rods 

 then acNiuiring the shape ofirregular perforated plates; no tables. 

 b. In dorsal perisome l^ranched X-shaped rods; in ventral, smooth rods in addition; 

 the arms of X-sliaped l^odies branched and often united; one Polian vesicle. 



paradoxa. 

 hh. Deposits in tlie form of delicate, slightly curved, very spiny rods; two Polian 



vesicles l-apiolmnir. 



an. Among the deposits, tables. 



h. Tables and rods or irregular perforated plates, but no buttons, 

 c. Rods but no plates. 



(7. Taljles with annular disk together with large rods branched at tips and cov- 

 ered with many small protuberances or granulations cinerascens. 



dd. Spire of tables often reduced. The small, more or less elongate rods are 

 characterized by being uneven, warted, distinctly undulated, or deeply 



incised so as to form a row of loops or holes along each side pervicax. 



cc. In addition to tables with small annular disk and twelve teeth to crown of 

 spire, small fenestrated plates, or branched X-shaped bodies. Blackish, 

 and large in life aim. 



