74 THE APODOUS HOLOTHURIANS 



more or less dentate; posterior end of plate abruptly narrowed so that there 

 are only a few small, smooth holes there; a bow across plate is, however, present. 

 The general appearance of the synaptids of this genus is like that of an 

 Euapta or Synapta, and the close relationship of the three genera is obvious. 

 The number of valid species is doubtful, but can only be determined by the ex- 

 amination of much material. All the described species are Indo-Pacific in 

 their distribution. 



KEY TO THE SPECIES OF OPHEODESOMA. 



A. Base of digits united by a membrane; color, reddish brown or lighter, either uniform or 

 spotted and marbled with other colors. 



Surface of body smooth, not roughened by anchors; cartilaginous ring absent. 



OLABKA 



Surface of body very rough from anchors; cartilaginous ring well developed. 



SPECTABILIS 



A A. Base of digits not united by a membrane; miliary granules numerous and aggregated 

 into heaps; color, grayish, mottled. 



Ground color obscured by numerous irregular spots and narrow dusky bands (some- 

 times white, without markings) GRISEA 



Ground color clear greenish-gray or dusky yellowish-brown, with few large blotches 

 (sometimes wanting) and broad dusky bands, some or all of which may be very 

 indistinct SERPENTINA 



OPHEODESOMA GLABBA. 

 PLATE V, PIG. 24. 



Synapta glabra Semper, 1868, p. 12; pi. 11. Calcareous ring and parti lies, pi. iv, fig. 8. 

 Euapta glabra Ostergren, 1898&. 

 Opheodesoma glabra Fisher, 1907. 



LENGTH. 300-900 mm., with diameter about 25 mm. 



COLOR. Uniformly reddish brown, the tentacles greenish brown; accord- 

 ing to Sluiter ('94), a large specimen from Saleyer was whitish, but possibly 

 it was bleached by the formalin in which it was preserved. 







DISTRIBUTION. Reported from Bohol, Philippines (Semper) ; Cebu, Philip- 

 pines (Theel); Ainboina (Sluiter); Bima and Saleyer, D. E. I. (Sluiter); 

 Thursday Island, Torres Strait (Sluiter); and Fiji Islands (Theel). Prob- 

 ably having the same range as godeffroyi, although not yet known from any 

 station west of Bima. 



REMARKS. Nothing is recorded of the habitat or habits of this species. It 

 seems to be well characterized by the dark color, smooth, thick skin, scattered 

 miliary granules, numerous stone-canals and polian vessels, and webbed digits, 

 but the constancy of these characters is not beyond question. 



