THE APODOUS HOLOTHUKIANS 95 



tegat to Porsanger Fjord, at depths of from 18-405 m. (Ostergren). Ap- 

 parently confined to the northern coasts of Enrope. 



Eemabks. — This curious little synaptid is easily recognized by the unusual 

 number and form of the tentacles, both of which peculiarities are remarkably 

 constant. It has been often confused, nevertheless, with Leptosynapta inharens, 

 according to Ostergren ( :03), but usually occurs at greater depths and is com- 

 monly found on a clay bottom. For a full and admirable description, see Oster- 

 gren ( : 05rt ) . 



Labidoplax media. 



Lab id pi a. r media Ostergren, 1905a. p. CLViii. Calcareous particles, fig. II B. 



Length. — 30-50 mm. 



CoLOK. — Not given, but the skin is said to be "thin, transparent." 



Distribution. — Bergen, Norway (Ostergren). 



Remarks. — The tentacles easily distinguish this species from the preceding 

 and the anchor-plates from all other known synaptids. Nothing more is known 

 of its anatomy or habits than is given by Ostergren. 



LABroOPLAX digitata. 



Synapta digitata Montague, 1815, p. 2"^; pi. iv, fig. 6. 



Synapta digitata Woodward and Barrett, 1858. Calcareous particles, pi. xiv, figs. 



1-17. 

 Holothiiria inJiwrcns Delle Chiaje, 1823, p. 124. 

 Cliiridota chiaii Grube, 1840, p. 41. 

 Labidoplax digitata Ostergren, 18986. 



Length. — 250-350 mm., with the diameter when fully extended one-thirtieth 

 to one-fortieth as much. 



Color. — Yellowish or reddish white, more or less heavily pigmented with 

 brick-red, especially on the dorsal side, which is often sharjjly in contrast with 

 the lower surface. 



Distribution. — Eeported from numerous stations on the coasts of Great 

 Britain, France, Spain, Italy, and Austria to depths of 618 m. (Herouard). 

 Lamport ('89) refers a fragment from near the mouth of the Congo to this 

 species, but admits the possibility of error. Probably confined to the coasts of 

 western and southern Europe and perhaps northern Africa. 



Remarks. — According to Semon ('87), this species is probably not strictly 

 subterranean, but lives on the bottom, where its rather peculiar coloration is 

 apparently protective. He says further that small individuals do not occur at 

 Naples, although the auricularije are common enough. For further notes on 

 habits and phj'siology, see his paper, and for a very detailed account of the 

 development his later report ('88). Ludwig ('98fl) says the anchors of this 

 species are from 170 to 310 /a in length, while those which I have meas- 



