HAWAJIAN HOLO.THURIANS— FISHER. 643 



DESCRIPTION OF SPECIES. 



Class HOLOTHURIOIDEA. 



KEY T() FAMILIES AND (iENKHA OF HAWAIIAN 1 1( )I.()TH FKIOIDEA. 



a. Witli pedicel.s or papill;e or botli. All aiubulacral appendages arise from tlie 

 radial canals, appearing as a cirele of tentacles about the mouth, and as pedicels 



or papilhe, or both, over rest of body Order Actinopoba. 



h. Tentacles more or less peltate. No retractor muscles. 



c. Respiratory trees present Holothuriid.k. 



d. Tentacle ampullae well developed. Madreporic canals often numerous, 

 never attached to body wall. Vascular system forming a rete mirable in 



connection with left respiratory tree Holothuriin.t.:. 



e. Genital tubes in a tuft on left side of dorsal mesentery. 



/. Anal teeth present Actixopyca. 



/. Anal teeth al)sent. 



y. Ambulacral appendages scattered over whole body and usually with- 

 out arrangement in rows; less connnonly arranged in longitudinal 



banils on ventral surface IloLoTiirmA. 



gg. Ambulacral ai)iien(lages only on the radii, and in double rows. 



TjAHIDODEMAS. 



ee. Gonad in aright and left tuft, no anal teeth; pedit'els on the 3d ventral 

 radii, mostly in longitudinal bands. Dorsal surface with papilke, often 



on warts Stichopus. 



dd. No free tentacle ampulhe. Madreporic canal single and usually in con- 

 nection witli body wall; only exceptionally a rete mirabile present. 



Syxallactin.t^. 

 e. Genital tubes only in a left tuft. Anus not in a vertical furrow. Ventral 

 surface somewhat flattened. Ambulacral appendages in form of many 

 small scattered pedicels, usually largest on lateral ventral am])ulacra. 



]\Iesothuria. 

 ee. Gonad in a right and left tuft. 

 /. Anus in a vertical furrow. Pedicels and papilhe unusually small, 

 those of dorsum nearly rudimentary; pedicels of lateral ventral 

 ambulacra more prominent than rest. Deposits often wanting. 



PSEUDOSTICHOPUS. 



ff. Anus not in a furro\\-, terminal or sul)dorsal. Body more or less 

 depressed, usually with a border or l)rim. 



g. C-shaped deposits present Bathyplotes. 



gg. No C-shaped deposits. Pedicels only on middle an<l liinder part of 



midventral radius; deposits often wanting P.elopatides. 



cc. Respiratory trees absent. No rete mirabile. No tentacle ampulhe. Dorsal 

 surface with large iiajnlht", ventral with very large i)edicels, always in rows. 



Madreporic canal ojjening to exterior. Deep-sea forms P^lpidiid.t^. 



d. In the stiff skin neither wheels nor tables. Above the jjedicels of lateral 



ventral radii a series of large tlank-papilla?. 



e. Pedicels of ventrolateral radii in two series; remarkably long flank and 



dorsal papilhe; papilhe of dorsal radii in two series; deposits very large 



X and Y shaped rods, and in papilhe very long simple rods perforated 



at tips. Anus ventral Scotodeima. 



ee. Pedicels of ventrolateral radii in a single series, those of dorsal in either 

 one or two series. Deposits, large crowded si)iny rods and spiny ellip- 

 soids Orphnurgus. 



