NO. 1555. HAWAIIAN HOLOTHURIANS— FISHER. 701 



With the exception of one of the rods of wall of gonad all the accom- 

 panj'ing tigures represent the deposits enlarged sixty-tive times. 

 This affords an easy method of comparison for deposits from different 

 parts of the body. Thus it is seen at a glance that the rods of the 

 dorsal perisome are very much larger than those of the venti-al, etc. 

 This remarkable species differs from Scotodeima setlgerutn Ludwig 

 in the greater development of the papillae, in the diversity in the 

 number of dorsal papilltB of inner and outer series, in the form and 

 greater size of the deposits, particularly those of the ventral and dorsal 

 perisome, in the number of tentacles, and in the form of the calcareous 

 ring, the latter being composed of radial and intorradial pieces. The 

 radial piece is pierced by a hole. If the figures of deposits of vitreum 

 are compared with those of setigerum"^ (the magnification being taken 

 into account), the difference in size is at once apparent, especially in the 

 rods of dorsal perisome and of papilla. The rods of the pedicels also 

 present important points of difference, best appreciated by a compari- 

 son of figures. Possibly the difference in the calcareous ring is most 

 important, the interradial pieces being absent in setlgerum . S. vitreum 

 differs from S. protect lun Sluiter* in the outer form, number of ten- 

 tacles, form of calcareous ring, and in the shape of the deposits. It 

 must be remembered that the commonest form of rod in the dorsal 

 perisome of S. vitremn. is the simple unbranched one. In both the 

 other species the four-armed kind appear to be the only ones, and are 

 considerabl}' smaller than in vitreum. On the whole vitreum appears 

 more nearly related to protectuin^ which was taken by the Siboga 

 expedition in latitude 0^ 34' 6" north, longitude 119° 8' 5" east, 1,301 

 meters. S. setigerum was dredged by the fisheries steamer Albatross at 

 Station 3362, east of Cocos Island, 1,175 fathoms. 



Genus ORPHNURGUS Theel. 



Orphnurgns Theel, Preliminary Report on the Holothuridfe of H. M. S. Chal- 

 lenger, CEfv. Ak. Forh., Bihang V, No. 19, 1879, p. 8; Challenger Holothurio- 

 idea, Pt. 1, 1882, p. 82. Type, 0. asp^r Theel. 



Tentacles 15 to 20, rather large, nonretractile. Lateral ambulacra of 

 ventral surface with very large pedicels disposed in a single row all 

 along each side of that surface, and with another series of slender, 

 flexible processes placed above pedicels all along each side of body. 

 Odd ambulacrum naked. Dorsal surface with a more or less crowded 

 series of numerous long papillae disposed in one or tw^o rows along each 

 dorsal ambulacrum. Integument with deposits in the form of smooth 

 or spiny rods sometimes dichotomousl}^ branched, or rods ti'ansformed 

 into solid large ellipsoids. 



«Lnd\vig, Mem. Mus. Comp. Zool., XVII, No. 3, Oct. 1894, p. 72, pi. vii, fig.s. 7-13; 

 pi. VIII, fig. 1-4. 



^Siboga Holothurioidea, 1901, pi. ii, fig. 7; pi. ix, fig. 4. 



