6 TWELFTH AiraTTAL REPORT. 



the system of mappina:, aud of description now being carried on, 

 could be extended over the rest of the state with the present force 

 in about two years. But as the printing of work already prepared, 

 and the preparation of maps and manuscript for future publication, 

 require much time, the completion of the survey cannot be looked 

 for before the close of the fourth year from this date. In addition 

 to this, other matters demanded by the law of the survey are very 

 important, but have been kept in abeyance pending the completion 

 of the strictly geological portion. This will require further time 

 and other workmen. It is to be hoped that the regents will always 

 be able to make an annual increment to the scientific knowledge 

 of the state, in some of the departments of investigation covered by 

 the law of the survey, and that the annual reports will successively 

 become more aud more valuable as they become more numerous. 



Dr. P. L. Hatch, who has charge of the investigations in the 

 ornithology of the state, has signified his intention to render his 

 final report on the same by or before the spring of 1885. 



Mr. C. L, Herrick has been given the mammalogy of the 

 state, with a view to the collection of skins and skeletons for the 

 museum, and the preparation of a final report on the same for pub- 

 lication in about two years. 



The only field-work done in 1883, was that performed by myself 

 in Dakota and Rice counties, including, however, further sup- 

 plementary observations in Mower and Olmsted counties, and a 

 visit to some of the localities of red quartzyte in the southwestern 

 part of the state. 



Additional cases will soon be placed in the south room of the 

 museum, intended for the reception of the collections of Dr. H. C. 

 Hovey. representing the stalactitic deposits of caves. This valua- 

 ble collection has kindly been loaned to the University, on deposit, 

 with the only condition that it shall be well kept. 



Further additions have been made to the specimens belonging to 

 the general museum, through the agency of the survey, and by 

 donation by the following individuals: W. H. Scofield, of Cannon 

 Falls, and James B. Alexander, of Minneapolis, and by several 

 others. 



These are all enumerated in the accompanying list of accessions. 

 Exchanges have been made with A. S. Tiffany, of Davenport, Iowa, 

 and John Eyerman, of Carbondale, Pennsylvania. 



The final paper of Mr. Herrick on a portion of the Crustacea of 

 Minnesota is presented in this report, illustrated by a number of 

 octavo plates. 



