No. Title 



* 44. Echo-ranging for fish schools and observations on temperature and 



plankton in waters off Central California in the spring of 1946. By 

 Osgood R. Smith and Elbert H. Ahlstrom. 1948, i + 30 pp. , 

 1 3 figs. , 9 tables. 



* 45. Waterfowl breeding conditions- summer 1947. By Cecils. Williams 



et al. 1948, i + 101 pp. , 15 figs. , 21 tables. 



* 46. Red tide. Progress report on the investigations of the cause of the 



mortality of fish along the west coast of Florida conducted by the 

 U.S. Fish and Wildlife Service and cooperating organizations. By 

 Paul S. Galtsoff. 1948, iii + 44 pp. , 9 figs. , 8 tables. 



* 47. Development of fishery statistics in the North Atlantic. By George A. 



Rounsefell. 1948, i + 18 pp., 9 figs., 1 table. 



48. Not issued. 



49. Not issued. 



* 50. Estimation of the troll catch of Columbia River chinook salmon, 



Oncorhynchus tschawytscha. By Ralph P. Silliman. 1948, ii + 15 pp. , 

 4 figs. , 10 tables. 



* 51. A survey of the Columbia River and its tributaries with special refer- 



ence to the management of its fishery resources. I. Introduction. 

 By Willis H. Rich. 1948, i + 26 pp. , 5 figs. , 1 table. 



* 52. Outlook for the Alaska herring fishery in 1948. By L. N. Kolloen 



and C. H. Elling. 1948, 23 pp., 2 figs., 13 tables. 



* 53. History, development, and problems of electric fish screen. By 



Harlan B. Holmes. 1948, ii + 62 pp. 



* 54. A record of pilchard eggs and larvae collected during surveys made 



in 1939 to 1941. By Elbert H. Ahlstrom. 1948, i + 76 pp. , 6 figs. , 

 22 tables. 



* 55. A report upon the Grand Coulee fish- maintenance project, 1939- 



1947. By Frederic F. Fish and Mitchell G. Hanavan. 1948, 

 iv + 63 pp. , 3 figs. , 24 tables, 6 plates. 



* 56. Observations on the horizontal distribution and the numbers of eggs 



and larvae of the northern anchovy (Engraulis mordax) off California in 

 1940 and 1941. By John C. Marr and Elbert H. Ahlstrom. 1948, 

 i + 13 pp. , 4 tables. 



* 57. Control of deer irruptions in Nevada. By C. M. Aldous. 1948, 



i + 9 pp. , 4 figs. , 3 tables. 



