[319] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 25 



males. The males, however, sometimes occur swimming free at the 

 surface in vast numbers. They swim with an undulating motion, and 

 are quite conspicuous on account of the bright red color of the middle 

 region of their bodies. Mr. S. I. Smith observed them swimming in 

 this way, in the daytime, in August, at Fire Island, on the southern 

 side of Long Island, where they occurred in incredible numbers and 

 were eagerly pursued by the blue-fish, which at such times would not 

 take bait. We often caught them in Vineyard Sound, in the evening, 

 at the surface, with towing-uets. These worms must, therefore, con 

 tribute largely to the food of many fishes. It is very common on our 

 sandy shores as far south as South Carolina. A third species, Nereis 

 pelagica* (Plate XI, figs. 52-55,) is abundant under stones farther north, 

 but in this region is chiefly found on shelly bottoms, in the deeper wa 

 ters of the sounds. These three species of Nereis are called &quot; clani- 

 worms&quot;by the fishermen. Two large species of worms belonging to 

 the genus Rhyncliobolus (formerly Glycera) are often met with in bur 

 rows, in the mud beneath stones. These are pale reddish, deep flesh- 

 colored, or dull purplish red, and rather smooth-looking worms, thick 

 est in the middle, and tapering to both ends. They have a large pro 

 boscis, armed at the ends with four black, hook-like jaws, and are re 

 markable for their rapid spiral gyrations. They belong more properly 

 to the muddy and sandy shores, and will, therefore, be -mentioned more 

 particularly in another place. They are represented on Plate X, figs. 

 43-46. Ophelia simplex occurs under stones at half-tide, and below. 



The Marphysa Leidyi (Plate XII, fig. 64) is a large and handsome 

 worm, occasionally met with under stones at low-water mark, but is 

 more common on shelly bottoms in shallow water off shore. It grows 

 to the length of six inches or more, and its body is flattened, except 

 toward the head, where it becomes much narrowed and nearly cylin 

 drical. It is yellowish or brownish red, and brilliantly iridescent. The 

 branchia3 are bright red, and commence at about the sixteenth segment j 

 the first ones have only one or two branches, but farther back they be 

 come beautifully pectinated. There are six unequal caudal cirri, the 

 lower lateral ones longest. It is furnished with powerful jaws, and is 

 carnivorous in its habits. 



A small but very active worm, PodarTce obscura V., (Plate XII, fig. 61,) 

 is often found in large numbers beneath stones. These are dark brown 

 or blackish in color, sometimes with lighter bands. They come out at 

 night and swim at the surface in vast numbers. They are also often met 

 with at the surface among eel-grass, in the daytime, in large numbers. 

 A large and very singular worm, which burrows and constructs tubes 

 in the mud and gravel beneath stones, is the Cirratulus grandis V., 

 (Plate XV, figs. 80, 81.) This is usually yellowish brown, dull orange, or 

 ocher colored, and is remarkable for the numerous long, flexible, reddish 

 or orange cirri that arise all along the sides. Another very large and 

 interesting worm, often associated with the last, both among and under 

 3 V 



