DEPARTMENT OF MARINE INVERTEBRATES. 229 



she is expected to remain during the entire summer. During the fiscal 

 year up to May 4, 1890, 133 dredge-hauls were made, in depths of 7 to 

 552 fathoms (station numbers 3077-3209). The zoological collections 

 obtained are now at the Fish Commission laboratory in Washington. 



The steamer Fish Hawk was engaged in scientific inquiries only from 

 July to October, 1889, during which time she was at work upon the 

 oyster grounds of Long Island Sound, between South Nor walk and 

 New Haven. This survey was conducted chiefly for the purpose of 

 ascertaining the characteristics and condition of the grounds, and of 

 determining means of lessening the ravages of the natural enemies of 

 the oyster. The natural history of the region being comparatively 

 well known, only a few specimens were saved from the dredgings. The 

 schooner Grampus was occupied during the summer of 1889 in making 

 a survey of the mackerel region south of New England, under the 

 direction of Prof. William Libbey, jr., of the College of New Jersey. 

 The area examined had a width of about 70 miles, and extended sea- 

 ward a distance of about 130 miles from the coast, or well into the Gulf 

 Stream. The work was principally of a physical character, having 

 reference to temperature, densities, currents, etc., but important collec- 

 tions of surface-animals were made, and a part of these are now being 

 studied by Prof. W. K. Brooks, of John Hopkins University. 



Another branch of inquiry that has grown up within the past two 

 years has been the systematic investigation of the interior lakes and 

 rivers. This work has been carried on mainly under the direction of 

 Dr. David S. Jordan, and in the interest of fish-culture and the 

 fisheries. Large collections of fishes have been made, and attention 

 has also been paid to the aquatic invertebrates, especially the cray- 

 fishes. During the year just ended the investigations have extended 

 to the following States and Territories : Georgia, Alabama, Louisiana, 

 Ohio, West Virginia, Indiana, Iowa, Missouri, Arkansas, Colorado, 

 Utah, the Yellowstone Park, and Kadiak, Alaska. 



