6G PIIOCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



An incomplete table is shown in Theel's figure. M\ stages between 

 the simple bifurcated, or perforated, ends of the rays to the completed 

 disk ma}' be observed. TheeFs suggestion that the two C-shaped 

 deposits he observed belonged to another species is i)orne out by the 

 absence of any such spicules in the six AIlM/tross specimens. 



Spicules of the tentacles. — The supporting rods (tig. 12) vary greatly 

 in size and degree of curvature. They ma}' be straight or form a 

 semicircle, or the curvature may be represented by an acute angle. 

 Generally the ends are perforated. The rods are smallest at the tips 

 of the tentacles. 



Size of rods in millimeters. — Length of chord. 0.06 to 1.4; width 

 of rod, 0.008 to 0.08. 



Polian vesicle. — Only one in each of the six individuals in contradis- 

 tinction to TheeFs, which had two. 

 Form, cylindrical. Length, 11.0 to 

 24.0 mm.; average, 13.5 mm. 



Stone cannl. — Single, in dorsal 

 mesentery with madreporite adher- 

 ent to coelomic epithelium. Length, 

 Fig. 12.— stichopus challengeri. Curved fj.O to 18.0 mm.; average, 13.0mm. 



SUPPORTING ROD OF A TENTACLE. ( X 50. ) TV/f 1 • i. T 1 i' J /• 



Madreporite. disk lormed (in one 

 case spherical) with stone canal attached to one edge. Diameter, 1.0 

 to 3.0 mm. 



Gonads. — In both sexes like a string of beads. Gonaduct accompa- 

 nies the stone canal anteriorly, joining the genital papilla just posterior 

 to the madreporite. Five specimens were females, one male. 



Respiratory trees. — Present in three specimens, with two branches 

 as described b}' Theel, except in one individual, which has three. 

 Length, trunk, 5.0 to 12.0 mm.; average, 8.0 mm.; longest branch, 

 30.0 to 59.0 mm.; average, 39.7 mm.; shortest branch, 23.0 to 43.0 

 mm.; average, 30.7 mm. 



Habitat. — Lat. 46^ 53' 8.; long. 51^ 52' E.; depth, 550 fathoms 

 (Theel, Challenger Report, 188()). Naha Bay, Behm Canal, southeast- 

 ern Alaska, Uyak Bay, Kadiak Island, Shelikof Strait {Alhatros-s, 

 Alaska Salmon Investigations, 1903). 



LITERATURE. 



1883. Bell, F. Jeffrey. On the Spicules of Ciicumaria hyndmanni, C. culcigera, and 



two allied forms. Jour. Roy. Mic. Soc. London, (2), III, pp. 481-484. - 

 1899. BiDENKAP, Olaf. Troms0sundets Echinodermer. Tromso Mus. Aarsh., Hft. 



20, pp. 104-112. 

 1835. Brandt, Joh. Frid. Prodromus descriptionis aninialium ab H. Mertensio 



observatorum. Ease. 1. 

 1883. Bush, Katharine J. Proc. U. S. Nat. Mus., VI. 

 1901. Clark, Hubert Lyman. The Holothurian.s of the Pacific coast of Nortli 



America. Zool. Anzeig., XXIV, pp. 162-171. 



