TROPICAL PACIFIC HOLOTHURIOIDEA. 129 
MOo.LPabDrpDaek. 
Molpadia bathybia,! sp. nov. 
Plate 3, fig. 2; Plate 4, fig. 5, 6. 
Length 50 mm., of which about 5 mm. is caudal appendage; diameter 
about 17 mm. Tentacles contracted out of sight and whole oral disk more or 
less shrunken. Body-wall, very thin. Color, gray. No phosphatic deposits. 
Caleareous particles, tables only but these very abundant though not crowded. 
Tables not perfectly symmetrical but not notably asymmetrical, and the disks 
never have projecting rods, nor do they tend to narrow down in the posterior 
end into supporting rods; disks (Plate 4, fig. 5) 200-300 » across with three 
primary holes, three secondary holes, often nearly as big, and not uncommonly 
additional marginal holes, so that there may be twenty or even more perfora- 
tions; spire (Plate 4, fig. 6) made up at base of three rods which quickly fuse 
into a smooth straight rod with blunt tip, 200-250 u high. 
Station 4670. Peru: west of Palominos Light House, 105 miles. 3,209fms. Bott. temp. 35.4°. Fne. 
dk. br. m. 
Station 4672. Peru: southwest of Palominos Light House, 88 miles. 2,845 fms. Bott. temp. 35.2°. 
Fne. dk. br. infus. m. 
Two specimens. 
The holotype is from station 4672. The other specimen (Plate 3, fig. 2) is 
slightly smaller but has the same proportions, with the tentacles somewhat less 
contracted and apparently fifteen in number. There are no phosphatic bodies 
and the calcareous particles are as in the holotype. This species is nearly allied 
to M. arctica but the tables are markedly different. In the absence of phos- 
phatic bodies and supporting rods and the total lack of anchors and plates, 
bathybia is easily distinguished from all the species hitherto known from the 
eastern tropical Pacific. 
Molpadia holothurioides. 
Plate 3, fig. 1. 
Cuvier, 1817. Reg. Anim., 4, p. 24. 
Molpadia musculus Risso, 1826. Hist. Nat. Europe, 5, p. 293. 
In Apodous Holothurians (Washington, 19087), I accepted holothurioides 
as the type of the genus Molpadia but did not accept it as a valid specific name 
within the genus, placing it instead as a questionable synonym under M. mus- 
' Ba6bBvos = deep-living, in reference to the unusual depth of its habitat. 
? Although dated 1907, this book was not issued until January, 1908. 
