MUSEUM OF COMPAKATIVE ZOOLOGY. 45 



ACTINARIA. 



Adamsia sociabilis Verkill. 



Adamsia sociabilis Verbill, Amer. Jour. Sci., XXIII., March, April, 1882, pp. 225, 



314, 315. 



Plate VIII. Figs. 2, 3. 



Column slender and long in full expansion, very changeable, smooth, with 

 pores (cinclidse) near the base; disk a little wider than the column; tentacles 

 small, slender, in two circles, often held alternately erect and recurved. Mouth 

 often protruded. 



Color of column translucent, and usually conspicuously striped with alternate 

 pink a»nd flake- white longitudinal bands, the latter narowing upward; tenta- 

 cles pinkish; mouth with pink lips, crossed by darker lines, between the 

 small lobes. Height in expansion, about 10 to 14 mm. 



This species is always carried about by a small hermit-crab {Catapagurus 

 socialis Smith, formerly Hemipagurns), as represented in our figure. 



It starts upon a small shell, usually Cadulus, or a pteropod (Gavolina), occu- 

 pied by the crab when young. The base becomes much expanded and bilobed, 

 the lobes often surrounding the aperture of the .shell, and uniting beneath. 



The basal disk, as it enlarges, secretes a thin greenish or brownish chitinous 

 pellicle, which covers the shell and extends far beyond its aperture, thus in- 

 creasing the space for the crab. Eventually the shell is i;sually entirely dis- 

 solved or absorbed, and in its stead there is only the conical or hood-shaped 

 horny pellicle, in which the crab protects his abdomen. The crab is an active 

 species, and habitually exposes more of its body than is usual in the group. It 

 is probably able to swim free. The disk of the actinian, usually, if not always, 

 is held downward, beneath and behind the legs of the crab. This position 

 would be favorable for obtaining its share of the food, when the crab is eating. 



This species was taken by the, Blake, at Station 344, in 129 fathoms, 

 N. Lat. 40° 1', W. Long. 70° 58'. 



It was taken off Martha's Vineyard, at many stations, in 76-410 fathoms, 

 by the U. S. Fish Commission, in 1880, 1881, and 1882. 



Sagartia abyssicola Verrill. 



? PheUia abyssicola Koren & Dan., Fauna Litt. Norvegiae, III., 1877, p. 78, pi. 9, figs. 



3,4. 

 Sagartia abyssicola Verrill, Amer. Jour. Sci., XXIII., 1882, pp. 314, 315. 



Plate VI. Figs. 1, 1 b, 1 c. 



Base broad, adherent, expanded and thin at the edges, often clasping the 

 tubes of Hyalincecia artifex, and also attached to pebbles and shells. Column 



