TROPICAL PACIFIC HOLOTHOBIOIDEA. 129 



MOLPADIIDAE. 



Molpadia bathybia, 1 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. 

 Calcareous 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 n 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 w^ith blunt tip, 200-250 n high. 



Station 4670. Peru: west of Palominos Light House, 105 miles. 3,209 fms. 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. 



Ctjvier, 1817. Reg. Anim., 4, p. 24. 



Molpadia ?nusculus Risso, 1826. Hist. Nat. Europe, 5, p. 293. 



In Apodous Holothurians (Washington, 1908 2 ), 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- 



1 /?a0i>/?ios = deep-living, in reference to the unusual depth of its habitat. 



2 Although dated 1907, this book was not issued until January, 1908. 



