_Terebella_ (_Polymnia_) _nebulosa_ Mont. is distinguished by its bright red colour, spotted with white; it is 6 or 7 inches in length, and ½ inch across. Large specimens of this beautiful worm may be obtained at Weymouth and elsewhere on the south coast, where it lives in about 14 fathoms. Each gill appears much more arborescent than in the preceding (Fig. 176, B); it consists of a main stem, from which comparatively few branches arise; these subdivide frequently, and the terminal branchlets are quite short. The "gland shields" are fourteen to sixteen in number. The tube is of mud. North Sea and Mediterranean. _T._ (_Leprea_) _lapidaria_ L. is 1 inch in length, orange-red in colour; and has 12 ventral shields. The tube, of fine mud, lies horizontally on the under surface of stones. _T._ (_Lanice_) _conchilega_ Pall. (the "sand mason") forms a very characteristic tube of sandy particles, small pebbles, and pieces of shell. It is buried in the sand, but a short portion protrudes, and bears, set round its edge, a fringe of branching sandy threads (Fig. 153) commonly seen on sandy shores between tide-marks. The worm may be distinguished from the preceding species by the fact that the series of fourteen to {329}seventeen gland shields are red, and continuous from segment to segment. The gill is shown in Fig. 176, C. North Sea, Atlantic, and Mediterranean. [Illustration: FIG. 176.—Gills of various Terebellids. × 4. A, _Amphitrite johnstoni_ Mgrn.; B, _Terebella nebulosa_ Mont.; C, _T. conchilega_ Pall.; D, _Nicolea_ Mgrn. (the finer branches are not indicated); E, _Pista_ Mgrn.; F, _Terebellides_ Sars (after Malmgren). _g_, Gill; _m_, mouth; _t_, tentacles.] _Nicolea venustula_ Mont. has only two pairs of equal, arborescent gills (Fig. 176, D); the tentacles are comparatively few. The animal, which is about an inch in length, is cinnamon-yellow with white spots, and has seventeen gland shields. 20 fathoms, North Sea and Mediterranean. _Pista cristata_ Müll. is readily recognised by the shape of the gills (Fig. 176, E), of which there are only two pairs. Each consists of a long peduncle, bearing a number of dichotomously dividing, rather spirally-arranged branches, the whole having the appearance of a "bottle-brush." The worm is 2 to 4 inches long, of greyish-red to yellow colour. Atlantic east and west (even at the mouth of the Congo), and Mediterranean. _Thelepus cincinnatus_ Fabr. is about the same length, pale red in colour, marked on its back with clear areas, giving the appearance of lacework. The gills are represented by numerous unbranched filaments arising separately in two transverse rows. The tube, which is adherent to shells, etc., along its whole length, is of thin, transparent, and flexible material like mica, covered with foreign bodies, and even with Polyzoa and Hydrozoa. 30 fathoms, Atlantic and Mediterranean.