ACTINOPODOÜS HOLOTHÜKIOIDEA. 



187 



Description: — Tentacles 15 (in one specimen only 10, in 

 another 16). One specimen measm-ed when fresh was 3 cm. long 

 and 1 era. broad. Dorsum vaulted, ventrum flat. The perisome 

 is colorless, the tentacles are brownish, and the viscera have in 

 general the same color, but are in some parts tinged with green. 

 Each of the dorsal ambulacra has a row of papilla3 11 to 17 in 

 number. The pedicels belonging to the lateral ambulacra are 

 ver}^ numerous and slender. They go around the anterior end of 

 the body, and do not seem to be very long. They form, at least 

 in the middle of the body, a double alternate row, but in the 

 smallest specimens tliey are in a single row. Tlie median ven- 

 tral ambulacrum is devoid of any appendage. 



Calcareous deposits are not very numerous. Subjected to a 

 rigorous search, the deposits could be discovered only in the dor- 

 sal papillae, lateral pedicels, and on the tips of the tentacles. I 

 can discover no large wheels such as are found in other species 

 of Lcetmogone. The deposits that are found on the papillae and 

 pedicels are small wheel- shaped plates and bent supporting rods. 

 Small wheel- shaped plates are very much Kke those described under 

 the same name by Thkel in Pannychia moseleyl, or the " Gitter- 

 plättchen " described by Ludwig in Lœtmopliasma fecundum. They 

 are most distinctly wheel-like in the dorsal papillae. There are 

 four primary openings, around which there is a circle of 



