337 [Verrill. 



time, but most fully at night, Tt seems more indifferent to clianges in 

 the density of the water, and in temperature, than any species with 

 which I am acquainted. It occurs associated with Metridium mcmjiim- 

 tum, and might be at first mistaken for the young of that species, but 

 differs greatly in habit and structure. It has absolutely longer tenta- 

 cles than the largest specimens of the latter, and lacks the fringe of 

 small ones at the border, as well as the fold of the column, Avliich in 

 the other appears in specimens that are less than a quarter of an inch 

 in diameter. The body is also much more slender and elongated, 

 and the base more narrow. 



This species bears some resemblance to Sagartia viduata Gosse, of 

 Europe ; more nearly to the living specimens as I have seen them at 

 the Aquarial Gardens in Boston, than the figures in Gosse's Actinologia, 

 but it differs essentially from that species, both in color and propor- 

 tions. 



Sagartia modesta Yerrill, sp. nov. 



Column cyUndrical in expansion, stouter than in the last species, 

 and with denser walls, which have not the semi-transparency of the 

 latter. In contraction it becomes short, cylindrical, about twice longer 

 than broad ; in full expansion four or five times as long as broad. 

 When partly contracted, a distinct fold of the surface near the upper 

 margin sometimes projects above the disk. Base well developed, 

 more so than in the preceding species, scarcely broader than the body, 

 adhering to stones, etc., readily and firmly. Tentacles about sixty in 

 number, marginal, moderately slender, tapering, rather short, less 

 than the diameter, of the disk. Color pale grayish ; the tentacles 

 lighter with a dark stripe down each side, enlarging at the base into 

 two rounded, blackish, lateral spots, and also widening into broader 

 spots of dark color at tAvo points between the basal spots and the ends 

 of the tentacles; the spots of the opposite sides nearly touching on the 

 inner surface, leave thus a central light stripe alternately narrow 

 and broader ; between the constrictions are usually flake-white spots. 

 Disk yellowish white, with darker radii. 



Mouth lobes small, but quite prominent, about eighteen in numljer. 

 Length, of the only specimen seen in expansion, 2.5 inches ; diameter 

 .6 ; length of tentacles .4 inch. 



Goose Island, Long Island Sound, under stones at low water mark; 

 not common. 



Metridium marginatum Edw. and Haime. 



''Actinia plumoiia!' and "^. senilis" Couthouy, Boston Journal Xat. 

 Hist. Vol. II. p. 57. Metridium marginatum Tenney, Natural History, 

 p. 523, figs. 515 to 517, 1865 ; A. and Mrs. E. C. Agassiz, op. cit. p. 7, 



PROCEEDINGS B. S. N. H.— VOL. X. 22 JLXY, 1866. 



