INVEETEBEATE ANIMALS OF VINEYAED SOUND, ETC. 347 



posing the curious bright red gills, which are shaped something like 

 miniature fir trees. The central stem is long and tapering, with a blood- 

 vessel winding spirally up to its summit, and another winding in the 

 opposite direction down to its base ; the basal part is naked, but above 

 this slender branches are given off, forming spirals all along the stem 

 and gradually decreasing in length to the tip; each of the branches con- 

 tains two slender blood-vessels. These branchiae commence at the fifth 

 segment and do not extend to the end of the body, the last ones being 

 much smaller, with few branches. The first four setigerous segments 

 have an acute, conical, papilliform ventral cirrus at the base of the lateral 

 appendages; on the fifth and following segments these become low, 

 broad, rounded, whitish tubercles, with longitudinal wrinkles or grooves, 

 and with a dark spot in the middle ; these appear to contain the glands 

 which secrete the cement used in constructing the lining of the tube, for 

 when attaching any additional object at the end, after adjusting it in thede- 

 sired position the worm constantly rubs this part of the lower surface back- 

 ward and forward over the edge of the tube and the object to be cemented 

 to it, until a perfect adherence is effected, and a smooth coating of firm 

 mucus is deposited, and this operation is repeated for every piece added 

 to the tube. It is very interesting to watch these worms, when in con- 

 finement in an aquarium, while engaged in constructing their tubes. 

 By placing bits of bright colored shells, tinsel, cloth, or even pieces 

 of bright colored feathers, near the tubes, they can be induced to use 

 them, and thus some very curious looking tubes will be produced ; 

 but they evidently prefer the more rough and homely materials to which 

 they are accustomed, when they can be had. The iridescent, opaline 

 colors of this species are usually very brilliant and beautiful, especially on 

 the back, head, and bases of the antennae. The general color of the body 

 is reddish brown, or deep brown, thickly specked with gray; the an- 

 tennae are paler brown; the lateral appendages yellowish brown, finely 

 specked with white and dark brown ; the gills usually blood-red, but 

 varying from light red to dark brown. There are two, small, black eyes 

 between the bases of the odd median and upper lateral antennae. This 

 species is often quite abundant on the sand-fiats near low-water mark, 

 especially where there is more or less mud mixed with the sand, but it 

 is still more abundant in the shallow or moderately deep waters off 

 shore, on muddy and shelly bottoms. It is difficult, however, to obtain 

 entire specimens with the dredge, for it usually merely cuts off the up- 

 per end of the tube, while the occupant retreats below; occasionally 

 the head of the worm is cut off in this way. On the shore, also, it is 

 not easy to obtain entire specimens unless the tubes be cautiously ap- 

 proached and the retreat of the worm prevented by a sudden and deep 

 thrust of the spade below it, so as to cut off the tube. This species is 

 carnivorous and has a very powerful set of black jaws, which are une- 

 qual on the two sides of the mouth, (fig. 68.) 

 The Marphysa Leidyi (p. 319, Plate XII, tig. 61) is allied to the pre- 



