706 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxii. 



deposits, and from O. (/laher (Walsh) in having one instead of two rows 

 of papill;e along each dorsal ambulacrum. In respect to deposits Inslg- 

 nls resembles (jlahev more than ciKper. Koehler and Vaney have very 

 adequately described and figured 0. [flaher. The deposits of this 

 species lack the large ellipsoids and the more elaborate cruciform 

 rods. 0. invalid/US Ktehler and Vaney has 15 tentacles, has simple 

 rods much like those of Scotodeima^ and a double row of papilla along 

 each dorsal radius. In respect to the deposits the species, as noted by 

 the describers, approaches Scotodeima. 



Genus L^^TMOGONE Theel. 



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

 lenger, (Efv. Ak. Forth., Bihang., V, No. 19, 1879, pp. 9-10; Challenger 

 Holothurioidea, Pt. 1, 1882, p. 73. Type, L. wyville-thomsoni Theel. 



Tentacles 15 to 20, rather large, not retractile. Lateral ambulacra 

 of ventral surface with large or medium-sized pedicels disposed in a 

 simple series all along each side of that surface. Odd ambulacrum 

 naked. Dorsal surface with long or short flexible processes or papillae 

 disposed in a single or double series all along each of the ambulacra. 

 Perisome with numerous wheels and with rods and sometimes cruciform 

 bodies. 



LiETMOGONE BISERIALIS, new species. 



Plate LXXV, figs. 5, 6a; Plate LXXVIII, figs. 1, la^e. 



Body rather elongate, four and one-half to five times as long as 

 broad, tapering slight!}^ at posterior end, which is bluntly rounded; 

 anterior extremity rounded. Ventral surface flattened, dorsal well 

 arched. Mouth terminal but ventral; anus terminal. Tentacles im- 

 perfect, but apparently not more than 15; crowns peltate. Pedicels 

 slender, 8 to 10 mm. long at middle of body, numerous, about fifty 

 to a side, forming a single series along each ventro-lateral radius. 

 Midventral radius naked. Papilhx? rather short (3 to 5 mm.), forming 

 two series along each dorsal ambulacrum, about sixty-four papilUe to 

 each radius. Deposits: In ventral perisome, small wheels with twelve 

 short spokes and four rather large holes in the nave, two of the holes 

 being larger than the other pair, together with simple rods smooth or 

 uneven along sides and somewhat spiny and irregularly roughened at 

 tips. In dorsal perisome large and small wheels, the former particu- 

 larly about base of papillse. Large wheels with usually twelve spokes, 

 and a large nave with six equal perforations. Papillje with crowded 

 small wheels, a rudimentary terminal plate, and a few rods near tip. 

 Pedicels with much less crowded, small wheels, and many slightly 

 curved supporting rods, sparsely spiny on either terminal third; large 

 perforated (eiininal plate present. Color of formalin specimen grayish 

 violet. Length, about 90 mm. ; width, about 20 mm. 



