NO. 17 SMITHSONIAN KX PLOKA TIONS. I916 45 



STUDY OF THE MARINE INVERTEBRATE FAUNA OF CHESA- 

 PEAKE BAY 



The hydrographic and biologic study of Chesapeake Bay begun 

 by the U. S. Bureau of Fisheries in 191 5 was continued during the 

 past year. On two of the cruises of the steamer I'isli Haivk, used 

 for these explorations, the U. S. National Museum had a representa- 

 tive aboard with instructions to give particular attention to the inver- 

 tebrate fauna of the bay. 



Mr. J. A. ]\Iirguet was detailed for this work from April 20 to 

 April 26, 1 91 6, during which time dredgings were made at Stations 

 Nos. 8497 to 8536 inclusive. A few of these dredgings were made 

 in Lynnhaven Sound and in the vicinity of Cape Henry. The others 

 were in various parts of the Chesajjeake between the mouth and the 

 Patapsco River. But little opportunity was afforded for collecting 

 along shore, the only work of this kind lieing done during a brief visit 

 to the shores of St. Mary's River and Buckroe lieach. 



^Ir. W'illiam B. Marshall was detailed to the Fish Haivk for 

 similar work from July 12 to July 31, 191 6. During this cruise. 

 Stations Nos. 8593 to 8622 inclusive were investigated, extending 

 from the mouth of the bay to above the Patuxent River. Near the 

 capes the dredgings yielded rich returns, l)ut the fauna appears to 

 dwindle out to the northward. 



On this cruise, many opportunities occurred for collecting along 

 shore and in the inlets and back bays. Lynnhaven Inlet and its 

 shores, the shores of Msherman's Island and at New Point, Cedar 

 Point, and Solomon's Island were carefully examined. Lynnhaven 

 Inlet yielded some fine material and interesting data. xAt Cedar 

 Point a fresh-water lake of many acres in extent comes to within 

 a hundred feet of the bay, above which its banks are elevated InU 

 a few feet. A small mollusk (Amiiicola) is abundant in the floating 

 vegetal)le matter and seems to be the only molluscan life occurring 

 in the lake. 



With a small dredge operated from a motor-boat, five or six hauls 

 were made in Mogothy I5ay at depths of from 20 to t,2 feet. The 

 fauna proved to be very rich, probably owing to the narrow channel 

 and fair current and the clean shores and flats covered with sea- 

 grass. L'nfortunately the netting of the dredge was carried away 

 by the weight of a mass of coral. Having no means of making 

 repairs, the party returned to the ship which then moved to another 

 station, leaving the investigation of Mogothy Bay unfinished. 



