28 VERRILL OX THE POLYPS OF THE 



Edwardsia sipunculoides Stimpson-, MS. 



Actinia sipunculoides SlIMPSON, Marine Inv. of Grand Menan, p. 7, pi. 1, fig. 2 (1853). 



Plate I. figures 12, 13. 



Column very slender, elongated, cylindrical, the central portion traversed by eight longi- 

 tudinal sulcations, between which it is somewhat swollen in the form of broad, rounded, 

 slightly prominent ribs, crossed in contraction by numerous strong transverse wrinkles. 

 The inferior naked portion when expanded is about one half an inch in length, pointed at 

 the extremity, without any distinct basal disk, but capable of being greatly distended, and 

 in this condition of adhering to stones by its membranous surface. This region is marked 

 with eight white lines, which meet at the central point of the base and are continuous 

 with the eight sulcations of the column. These coincide with the corresponding internal 

 partitions, which are seen through the transparent walls. The upper naked portion, in ex- 

 pansion, is one third of an inch or more in length, smooth and cylindrical. The tentacles 

 are about thirty-six in number, arranged somewhat crowcledly in two rows close to the 

 margin. They are long, slender, tapering to a point, the outer ones a little shorter than 

 the inner, which are twice longer than the diameter of the disk ; mouth with four small 

 but prominent lobes on each side. 



The color of the central, sheathed portion is usually yellowish brown, but varies to 

 black, according to the situation and the color of the mud where found ; basal naked area, 

 pellucid yellowish white ; upper naked portion, yellowish, surrounded, about midway be- 

 tween the tentacles and sheath, by a ring consisting of eight lunate, arrow-shaped, or square 

 opaque white spots, which are close together and sometimes extend downward at their 

 lower angles, forming a white line along the sides of each invection ; sometimes there is 

 a trace of another ring of smaller white spots lower down ; tentacles transparent yel- 

 lowish white, sprinkled with numerous flake-white dots, sometimes with small white spots 

 at the outer base. Mouth and "stomach" bright red, the former generally prominent; 

 disk yellowish, with faint white radii, and white spots often surrounding the base of the 

 tentacles. 



Length of the largest specimens when in full expansion, about 5 inches ; in diameter, 

 .15 ; when contracted, about 1.5 inches in length. (Coll. Mus. Comp. Zool.) 



Eastport, Me., and Grand Menan, N. B., in gravelly mud under stones at low water. 



This interesting species has, as yet, been found in very few places, and, with one excep- 

 tion, very sparingly in its localities. In the vicinity of Eastport, Me., at a point just south 

 of Dog Island, I succeeded in obtaining several hundred specimens in a very short time 

 by turning over the large stones, when they were seen projecting from the mud, chiefly near 

 the edges of the stones, looking much like some species of worms. As many as fifteen or 

 twenty were sometimes found under a single stone. This locality was first discovered by 

 Dr. Stimpsou. They here occupy the lower third of the littoral zone. Some force is 

 usually required to pull them from their burrows, but this seems to be owing to the 

 distension of their bases rather than to any adhesive power. When put into sea-water 

 they expand readily and move about with worm-like gyrations. When touched, they sud- 

 denly jerk away the upper part of the body before withdrawing the tentacles. They feed 

 readily, like most Actinidcv, upon bits of clams and other mollusks. 



