No. Title 



* 30. Water quality studies of the Mississippi River. By Wesley S. 



Platner. 1946, 77 pp., 22 figs. , 29 tables. 



* 31. Studies of an ichthyosporidian-like parasite of oceanpout (Zoarces 



anguillarisj. By Leslie A. Sandholzer, Thomas Nostrand, and Leo 

 Young. 1945, ii + 12 pp. , 4 tables, 6 plates. 



* 32. Oyster bars of the Potomac River. By David G. Frey. 1946, 



93 pp. , 26 figs. , 27 tables. 



* 33. An investigation of fish-maintenance problems in relation to the 



Willamette Valley project. By Joseph A. Craig and Lawrence D. 

 Townsend. 1946, vii + 78 pp. , 10 figs. , 27 tables. 



* 34. Intraseasonal and interseasonal variations in average weight of 



Columbia River chinook salmon (Oncorhynchus tschawytscha), 1939-1945. 

 By Ralph P. Silliman, Willis H. Rich, and Floyd G. Bryant. 

 1947, 11pp., 5 figs. , 18 tables. 



35. Not issued. 



* 36. Studies on substitute containers for canned fishery products. By 



Norman D. Jarvis and Lynne G. McKee. 1948, ii + 26 pp. , 

 23 tables. 



* 37. Studies on gum extracts from Gracilaria confervoides (North Carolina). 



By Charles F. Lee and Leonard S. Stoloff. 1946, 12 pp. , 3 figs. , 

 3 tables. 



* 38 . Water quality studies of the Delaware River with reference to shad 



migration. By M. M. Ellis, B. A. Westfall, D. K. Meyer, and 

 W. S. Platner. 1947, i + 19 pp. , 11 figs. , 28 tables. 



* 39. Effects of aquatic weed infestations on the fish and wildlife of the 



Gulf States. By J. J. Lynch, J. E. King, T. K. Chamberlain, and 

 Arthur L. Smith, Jr. 1947, i + 71 pp., 11 tables. 



* 40. Evaluation of fisheries in determining benefits and losses from 



engineering projects. By Richard A. Kahn and George A. Rounsefell. 

 1947, 10 pp. , 4 tables. 



* 41. DDT investigations by the Fish and Wildlife Service in 1946. By 



Arnold L. Nelson and Eugene W. Surber. 1947, iii + 8 pp. 



* 42. Toxicity of phenyl-mercuric lactate for fish. By M. M. Ellis. 



1947, 6 pp. , 2 tables. 



* 43. Cattle losses and the coyote on a southwestern range. By Adolph 



Murie. 1947, i + 84 pp. , 2 tables, 3 maps. 



