ACTIKOruUOLS HOLOTliriUOIDEA. 20o 



the longest about onc-tliird of thu width of tlu' l)Oily, and in about 

 four rows, of which thu inner two arc soniotimos chstinctly 

 separated by a space from tlie outer two. Back naked in the 

 median dorsal interambnlaerum, with the exception of the genital 

 process in the anterior part. Integument soft and pliable, some- 

 times thin, sometimes thicker and spongy (the difference being 

 due to the state of preservation) ; colorless, more or less trans- 

 lucent, most so in the fresh state ; internal organs (especially 

 the light-colored ones like the genital organs) visible from the 

 surface. Color in alcohol, whitish grey without any white spots ; 

 in the fresh state, a beautiful hght violet, with deeper tints on 

 the dorsal papillae. A rather broad straw-colored streak on each 

 side of the dorsal surface and outside the outer series of dorsal 

 papilla3, becoming fainter toward the front, is visible in the fresh 

 state, but is lost in preserved specimens. Polian vesicle one, on 

 the left ventral interradius ; in one specimen 2.2 cm. long. 

 Genital organs paired, bushy. Stone-canal opens to the exterior 

 l»y a number of small openings, near the genital papilla, which 

 is in the anterior part of the median dorsal interambnlaerum. 

 When the area of the openings is somewhat circumscribed and 

 convex, it appears like a madreporic plate. 



Calcareous deposits in the general perisome consist of two 

 kinds of wheels: large wheels with six central rods and 9 — 12 

 spokes (textfig. o7b), and small ones with four central rods and 

 usually twelve spokes (c). Arcuate or spindle-shaped spicules are 

 present on the pedicels and tentacles (d). 



Bemarks : — This is by far the commonest of the holothuiians 

 found in tlie deeper parts of tlio Sagami Sea, exceeding greatly 

 in number Lcelmogonc riolacea Thkel, which is next to it in 

 abundance. 



