1892] 



MARYLAND ACADEMY OF SCIENCES. 



221 



f^ 



landward surface, two feet below low-water mark, a few 

 stems resembling those of Cordylophora. I transferred 

 them in a jar of tide water to the aspirated brackish water 

 of my aqnarinm, and in the course of a week several good 

 hydranths had made their appearance. Their habitat at 

 this point is considerably different from that at Fort Gov 

 ington. The water is much deeper and more clear, and 

 the colonies exposed to more violent waves. 



I made but slow progress in finding new 

 localities for Cordylophora until I had de- 

 vised a species of hand dredge furnished 

 with a long handle (Fig. 2), with which 

 I was able to reach down from a boat 

 or elevated dock to a depth of several 

 feet into the water and gather w^iat- 

 ever might be attached to the sides 

 of piles, piers, etc. With the aid of this 

 I found most of the localities described 

 below. 



The dredge proper consists of a |-inch 

 wrought iron shank set firmly into a stift", 

 oak 12-foot handle, and having two diver- 

 gent i-inch arms which are slightly curved 

 forward. The extremities of the arms are 

 joined by a thick, moderately sharp 4 by 

 li-inch cutting blade, set at an angle of 

 45° with the handle. The back of the ,/ 

 blade contains a row of perforations which, • ,■' 



with the arras, serve for the attachment 



n ,-, , Fig. 2.— Hand dredge. 



01 the net. 



Following the example of Kirchenpauer, who found 

 Cordylophora upon the buoys in the mouth of the river 

 Elbe (3, p. 283), May 22d, 1892, I began an examination 

 of the buoys of the Patapsco. I visited several between 

 a point opposite Fort McHenry and Light street bridge, 



