ACTIXOIN iDOrs IIOLOTHUUIOIDEA. 



13 



All tliB spauimens jne more or less coutriicteil. 



Description : — Tcnttieics 'JO, may ))e reduced tu 111 or to 10. 

 Color in alcohol, lighter or darker shades of lu'own. Some with 

 decided purple tinge, others appear bleached and white. Young 

 specimen translucent without color. Tentacles light yellow, in 

 young specimen of a decided orange color. 



Body cylindrical or subcylindrical, witliout any marginal 

 border between the ventrum and the dorsum. Tapers mut;li more 

 toward the posterior end than toward the anterior. Mouth 

 ventral, anus terminal. 



In the specimens which show the arrangement of the am- 

 bulacral appendages best, dorsal papillae are in six longitudinal 

 rows : one on each side at the boundary between the dorsum and 

 the ventrum and liclonging to each lateral ambulacrum, and two 

 belonging to each of the two dorsal ambidacra. Each papilla has 

 a large wartdike conical base, from the toi^ of wliich a much more 

 slender j) ipilla arises. In a specimen which sliows tliis best, the 

 whole dorsum appears as if it were covered entirely by these 

 conical warts, althougli in fresh specimens tliere must liave ])een 

 some space between and around their bases. The slender 

 terminal p;ipilla-like part is short in the jiosterior parts but 

 becomes as long as 8 mm. in the anterior region. The i)ai)illae on 

 the dorsal side of the mouth have small bases, but arc especially 



