KJO THE APODOUS HOLOTHUEIANS 



AA. — Anchors present, but if associated with more tlian a single plate, some of them have 

 3 or 4 arms. 

 B. — Auchoi's with only 2 arms and associated with a single plate. 

 C. — Anchor-plates large, about 400 ,11 long (plate x. fig. 23). 



Many tables with trifid base, the ends of each of the 3 arms expanded and 



perforated (plate x. fig. 24) brevicaudata 



None of the tables witli trifid l)ase makenzelleri 



CO. — Anchor-])lates small, about 130 /* long (plate x. fig. 9). 



Tables with more or less irregular, often trifid base coxcolok juv. . 



No tables at all present tridens 



BB. — Anchors commonly with 3 or 4 arms (plate x. fig. 25) polymorpha 



MOLPADIA OOLITICA. 



Plate X, Fig. 14. 



Cliirodota ooliiica Pourtales, 1851, p. 13. 



Molpadia borealis Sars, 1859, p. 174. 



Molpadia obUtlca Selenka, 1867. 



Embolus pauper Selenka, 1867, p. 359. 



Trochostoma thomsonii Danielssen and Koren, 1878, pp. 229-256; pis. i-iii. 



Trocliostoma [Molpadia) horrale Danielssen and Koren, 1879. pj). 124-126, 137: pis. 



T and VI. figs. 1-5. 

 ? .l?iZ7//'of/p;7»i7 />/f>r//.s/( Danielssen and Koren. 1S79. pp. 128-133, 135-131: pis. v 



and VI. figs. 11-19. 

 Trochostoma thom'sonil mariikifum Danielssen and Koren, 1882, p. 94; pi. xiii, figs. 



5-6. 

 Trocliosfoma horoalc Hoffman, 1882. 



Trochostoma (Mo]padla)odIiticiim Danielssen and Koren, 1882. 

 Trochostoma oolithicum Lampert, 1885. 

 Trochostoma ooliticum Theel, 1886ff. 



Length. — 100-135 mm., the diameter of the body about ono-fonrth as much; 

 the caudal appendage short and not often abruptly distinct. 



CoLOE. — In life grayish green and violet are the jirevailing colors, while 

 in preserved specimens dull gray and reddish or dark brown predominate; the 

 oral disc and caudal appendage are noticeably light-colored in contrast. The 

 exact coloration depends on the development of the phosphatic bodies; where 

 these are few, the general color is gray, with little brown, but when these are 

 abundant the color becomes more and more brown; in some specimens these 

 deposits become so numerous that the body is almost black. 



Distribution. — Reported from numerous stations in the North Atlantic and 

 Arctic oceans, from Florida Reef (Pourtales) and West Indies (Theel) to Spitz- 

 bergen and north thereof (Ludwig) ; also eastward through Barents and Kara 

 seas to Cape Chelyuskin, Siberia (Stuxberg) ; in the eastern Atlantic it is not 

 known south of 62° N., while in the western Atlantic and Arctic oceans it is not 

 known north of Labrador or west of the Faroes. Its real home seems to be the 

 Arctic Ocean, north of Europe and western Siberia, with a long southwestward 



