FROM CHESAPEAKE BAY. 137 



Eudendrium carneum, nov. sp. Plate 7, figs. 10 to 17. 



Trophosome. Hydrocanlus much branched, fascicled at its base and attaining a height 

 of 75 to 125 mm.; primary branches irregularly arranged on all sides of the hydrocaulus, 

 occasionally some of the branches near the base very large, being little less than the main 

 stem ; the secondary branches or branchlets arranged alternately on the upper side of the 

 branches ; hydrauths supported at the summits of small ramuli borne on opposing sides of 

 the branchlets and also at the extremities of the branches, branchlets and ramuli ; perisarc 

 firm, nearly colorless at the distal ends, deepening to a dark brown at the base, annulated 

 at the bases of the branches, branchlets and ramuli. Hydranths large and usually with 

 about twenty-four tentacles. 



Gonosome. Sporosacs in the male, composed of a number of spherical receptacles 

 arranged in a moniliform series of from three to five and borne in a crowded verticil. 

 Sporosacs in the female arranged in irregular, elongated groups of three to six, several of 

 which spring from one side of a branchlet or a ramulus ; the distal end of the ramulus 

 may or may not support a hydranth, each sporosac ornamented by a thickening of the 

 perisarc which leaves only the distal portion thin; this latter part finally breaks away, 

 forming a means of exit for the planula. The different sexes are usually found in different 

 colonies. 



Color. Hydranths vermillion, perisarc darkest in oldest parts ; female gonophores red, 

 planulae red, male gonophores red. 



Habitat. Attached to spiles of wharves, rocks and shells, in the littoral and coralline 

 zones. 



Locality. Fort Wool, Virginia, in the entrance to Hampton Roads. 



The rocks forming the piers and also the spiles of the old wharf at Fort Wool are coated 

 during June, July and August with immense quantities of these showy colonies that form 

 a miniature forest, extending at low tide as far as the eye can reach. The lower parts of 

 the colonies form dense tangled masses all matted together with thick growths of Pero- 

 phora, two or three kinds of sponges, Vesicularia, various forms of Vorticellidae, etc., etc. 



The arrangement of the branches and consequently the forms of the colonies vary 

 much according to the surrounding conditions ; if the colony is not restricted the branches 

 diverge from all sides and give a full, well-rounded growth about the main stem ; but they 

 are often so crowded that the branches are twisted and bent round into one plane, looking 

 as though they all sprung from two sides of the stem. I succeeded in raising a number of 

 colonies from the eggs ; the eggs passed into the planula stage, these became free-swim- 

 ming, finally they resorbed their cilia, became attached, and developing a hydranth and 

 hydrorhiza, with a covering of perisarc, began the formation of a new colony. 



One of the many planulae observed, developed after becoming attached, two hydranths 

 at once ; the two trending away from each other in nearly opposite directions, see Plate 7, 

 fig. 14. So many planulae were developing at the same time that the clear glass dish 

 became dotted all over with bright rosy spots where they had attached themselves. 



MEMOIKS BOST. SOC. NAT. HIST. VOL. Til. 18 



