INVERTEBRATE ANIMALS OF A^INEYARD SOUND, ETC. 419 



described froai specimens dredged by us in Vineyard Sound. It is often 

 liandsomelj' banded with light red and pale yellow. It is still a rare 

 species, but has been dredged also near New Haven. 



The Ascidians, with the exception of one or two additional species 

 seldom met with, are the same as those of the rocky bottoms, and they 

 often occur in immense quantities, especially the massive sandy ones, 

 Amarcccium 2)eUucidum, [yi. 4:01,) and the "sea-pork," A. stellatum, (p. 

 402,) which together often almost entirely cover the bottom over areas 

 many acres in extent. They furnish excellent hiding-places in the open- 

 ings and crevices between their lobes for numerous Crustacea and Anne- 

 lids, many of which can be easily secured by putting the masses of 

 these ascidians into buckets of water and leaving them until the water 

 begins to get stale, when they will come out of their retreats in large 

 numbers and seek the surface or edges of the water for oxygen. Or 

 they may be pulled apart directly and the various creatures secured at 

 once. 



The Molyula arenata (Plate XXXIII, fig. 251) is a nearly globular, 

 but often somewhat flattened species, which covers itself over with closely 

 adherent grains of sand or gravel. It is most common on sandy bottoms 

 but is found also on gravelly ones. 



The Cmia tenella is an elongated, erect species, attached at base to 

 rocks, dead shells, &c. It is remarkable for the transparency, whiteness, 

 and softness of its integument, and for the bright orange ocelli around 

 its orifices. It is rare in this region, but very common in the Bay of 

 Fundy. 



The Bryozoa are very abundant, especially on the shelly bottoms. 

 Some of them grow on algic, hydroids, ascidians, &c.; and many 

 form incrustations on the dead shells and pebbles. The two most 

 abundant and prominent species are Bugula turrita (p. 311, Plate 

 XXXIV, figs. 258, 259) and Escharella variahiUs, (p. 312, Plate XXXIII, 

 fig. 256.) The former grows attached to the various sea-weeds in great 

 quantities, forming delicate white plumes, often six inches to a foot in 

 length. The latter mostly forms calcareous incrustations over the sur- 

 faces of dead shells and pebbles, thin at first, but eventually becoming 

 thickened by the formation of layer over layer, until the crust may be- 

 come half an inch to an inch in thickness, with a tabulated and vesicu- 

 lar structure in the interior. The masses thus formed often closely 

 resemble genuine corals, especially some of the ancient fossil forms, 

 and they often occur in great quantities. When living the color is dull 

 red, but when recently dried they have a yellowish-green color, which 

 easily bleaches out, however, by exposure to the sun and air. Vesicu- 

 Iciria dichotoma, {]). AOij) Alcyonidium ramo.^wrn, (p. 404, Plate XXXIV, 

 fig. 257,) and Crisia ehurnea (p. 311, Plate XXXIV, figs. 260, 261) are 

 usually' abundant. Most of the remaining species have also been men- 

 tioned in the previous pages as inhabitants of rocky bottoms, or else 

 among the shore species. 



Among the species not jireviously mentioned are Cellepora scabra, 



