NO. 1555. HA WA II A N HOL TH URIA NS— FISHER. 693 



except for an occasional spine. No two are exactly alike. Those of 

 gonad are apparently larger than those of respiratory tree. The 

 former measure from about 0.09 mm, up to 0.22 mm., while the latter 

 seldom exceed 0.12 nun. in length. Rarely a small rod is unbranched. 

 The figures will give a good idea of typical shapes. 



This species is probably closely related to Pmudo^tlclwiyus mollis 

 Theel. It differs, apparently, in having a row of small but fairly 

 conspicuous wart- like processes forming an inconspicuous fringe, 

 as shown in the figure. The calcareous ring is of a slightly different 

 form, and the calcareous deposits of genital and respiratory tubes are 

 more branched and smaller. The dimensions may vary with age, how- 

 ever. The dimensions given b}^ Ludwig* are about twice as great as 

 those attained by deposits in this species. The internal organs are 

 much as described by Theel and Ludwig for mollis. This species dif- 

 fers, by the presence of the deposits, from Pseudostlehopus trachus 

 Sluiter and Pseudostlehopus pustulosus Sluiter from the East Indian 

 region. Pseudostlehopus oeculatus von Marenzeller from the region 

 of the Azores resembles this form in its deposits, but differs in the outer 

 character of form, distribution of ambulacral appendages, etc., as well 

 as in the presence of end plates in pedicels and deposits around the 



anus. 



Genus P^^LOPATIDES Theel. 



Pfelopatides Theel, Challenger Holothurioidea, Pt. 2, 1886, p. 154. Type, P. 

 confundens Theel. 



Tentacles 12 to 20, peltate, or subdigitate on the margin of crown; 

 no tentacle ampuUse; body more or less depressed often with a con- 

 spicuous overhanging border bearing a single series of numerous pa- 

 pillae; this border or brim obsolescent in some species except at fore 

 and hind ends of bod}^; pedicels form a double row on hinder third or 

 two-thirds of mid-ventral radius, and in some species also a single 

 i-ow along either ventro-lateral radius, in addition to papilla^; single 

 series of papillas on dorsal ambulacra; gonad in two tufts, a right and 

 a left; mouth ventral; aims dorsal or subdorsal. Deposits, when 

 present, simple, triradiate or four-armed rods, either smooth or spin}^, 

 with slightly branched tips; deposits often entirely wanting. A rete 

 mirabile sometimes present. 



PiELOPATIDES RETIFER, new species. 



Tentacles, 19 to 20, rather large; crown subcircular, fleshy, four or 

 five times divided, peltate. General form short and stout; length two 

 and one-half to four times width. Ventral surface more or less flattened, 

 the dorsal markedly convex. Mouth ventral, anus dorsal. Mid-ventral 

 radius with a double row of good-sized, spaced pedicels (about 28) 



«Mem. Mus. Comp. Zool., XVII, No. 3, 1894, p. 12. 



