404 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



The Alcyonidium ramosum (Plate XXXIV, fig. 257) is one of the most 

 conspicuous species, and is often very abundant, attached to rocks in 

 shallow water. In such situations we have often found arborescently 

 branched specimens, twelve to fifteen inches high, with smooth, cylin- 

 drical branches about a third of an inch in diameter. 



The Alcyonidium Mspidum (p. 312) does not appear to have been 

 recorded as from our coast, by previous writers, but it is one of our most 

 common species, and may almost always be found incrusting the stems 

 of Fucus at low- water mark, as well as the under surfaces of rocks ; below 

 low-water mark it is less abundant, generally incrusting Phyllophora, 

 and other stout, palmate algte. It is easily distinguished by the slender, 

 acute, reddish spines, of horn-like texture, which surround each of the 

 cells. It forms soft crusts of moderate thickness, gradually extending 

 over the surface of the sea- weeds to which it becomes attached. 



The A. Mrsutum has also been hitherto overlooked on our coast, but 

 is common, living under the same circumstances as the last, and some- 

 times associated with it, both above and below low-water mark. I have 

 found it in the greatest abundance in some of the large, rocky tide-pools 

 on the outermost of the Thimble Islands, east of Xew Haven. It was 

 there growing chiefly upon Phyllopliora membranifolia, in some cases en- 

 tirely covering and concealing the plant, from the base of the stem to the 

 tips of the fronds. It also often grows on the u Irish moss," Chondrtts 

 crispus, on rocky bottoms in shallow water. It forms rather thin, soft 

 crusts, which have small, soft papillae scattered over the surface ; from 

 the summit of each of these papillsea zooid protrudes, when they ex- 

 pand, and displays an elegant little wreath of tentacles, much as in 

 A. ramosum, (see fig. 257.) The A. parasiticum is also a species hitherto 

 neglected on our coasts. It forms thin crusts on algae and hydroids, 

 which generally become coated with a layer of fine sand or dirt. I 

 have not observed it at low-water, but have found it at the depth of a 

 few fathoms on rocky bottoms in Vineyard Sound. 



The Vesieularia dicliotoma V. is a very common species, both on 

 rocky shores, in pools and on the under side of stones ; and in shallow 

 water on rocky and shelly bottoms. It is also capable of living in 

 brackish water, and is frequent on the oyster-beds. It usually forms 

 csespitose clusters of many crowded, slender, white stems, each of 

 which is repeatedly forked, branching in a somewhat arborescent man- 

 ner. There is a little crowded cluster of small, dark-colored, oval or 

 pear-shaped cells just below each fork, the cells being sessile and 

 arranged in two somewhat spiral rows in each cluster. It generally 

 grows about an inch higb, but sometimes two or three inches. When 

 expanded each of the zooids protrudes from its cell-like body a delicate 

 wreath of eight slender tentacles. 



The Vesieularia cuscuta is a delicate, creeping species, which resem- 

 bles, in miniature, the u dodder-plant," (Cuscuta,) and creeps over other 

 bryozca and hydroids, very much as the dodder creeps over other 



