^T. cincinnatus.^ Two to four inches long; pale red; marked like lacework on the back; gills have numerous unbranched filaments arising separately in two transverse rows; tubes thin, transparent, flexible, and hung with foreign substances; attached along the whole length. GENUS ^Amphitrite^ [Illustration: /Amphitrite ornata./] ^A. ornata.^ Twelve to fifteen inches long; flesh-color, reddish, or brown; three pairs of red plume-like gills and numerous flesh-colored tentacles around the anterior end; tentacles constantly in motion and sometimes extended eight or ten inches; tubes a quarter of an inch or more in diameter, and firm, being composed of sand and mud. It is found under stones in mud, gravel, and sand at low-water mark from Cape Cod to New Jersey, often associated with /Cirratulus grandis/. GENERA ^Polycirrus^, ^Chætobranchus^ [Illustration: /Polycirrus eximius./] ^P. eximius^, ^C. sanguineus^. These are two species of bright-red, fragile worms, found under stones, in mud. They do not form tubes. The first is a small worm, the second twelve to fifteen inches long. Both have long, crowded tentacles extending in every direction and distended as the blood flows into them. /C. sanguineus/ has [pg183] tentacles sixteen inches in extent, and branched gills on short pedicels on the back. They are common in mud at low-water mark from Cape Cod to New Jersey. FAMILY ~AMPHICTENIDÆ~ GENUS ^Cistenides^ [Illustration: /Cistenides Gouldii./ ] ^C. Gouldii^ constructs conical free tubes of grains of sand in a single layer; body short and a little curved; head obliquely flattened; two broad groups of golden bristles turned upward on each side of the anterior end; one to two inches long; color light red or flesh-color, mottled with red or blue. This is a common worm, and its horn-shaped tubes are so plentiful as to attract attention on sandy shores. They will repay examination with a glass, so beautifully are they built. The worm has bunches of golden bristles arranged in two rows close to the flattened anterior end, which make a kind of operculum to the tube. This feature makes the species easy to identify. The worm is transparent; the internal organs showing through give it the various bright colors. It is found on sandy and muddy shores from New Jersey northward. FAMILY ~MALDANIDÆ~ The tubes of these animals are formed of sand, a short portion projecting, and are very abundant in certain places. There is a horny plate on the upper surface of the head, and the skin on the sides of the head is raised in folds. There is a funnel-like process at the posterior extremity; gills are lacking. Some of the segments in the middle of the body are longer than the rest. GENUS ^Clymenella^ [Illustration: /Clymenella torquata./ /a/, head and extended proboscis, front view; /b/, posterior end; /c/, entire animal, side view, natural size.]