nor forward in the article — they are concerned only 

 with the present. They therefore need supplemen- 

 tation by introductions, which supply this informa- 

 tion that headings, because of their brevity, cannot 

 give. 



Introductions, in contrast to headings, are com- 

 plex devices. They have five transitional functions; 

 therefore, a complete introduction is made up of 

 five parts. This manual defines the functions, 

 names the parts, and shows how to use them. 



The manual thus is concerned with the heading- 

 introduction technique, and its aim is to show how 

 we can use this technique to help the reader grasp 

 our idea fast. 



284. Microbiological study of iced shrimp: ex- 

 cerpts from the 1965 iced-shrimp symposium. 

 By B. J. Carroll, G. B. Reese, and B. Q. Ward. 

 May 1968, 17 pp.. 8 figs., 1 table. 



ABSTRACT 

 The presentations of studies of microbiology and 

 summarized results of the abridged histological 

 studies are reported. How marine and land bacteria 

 cause spoilage under refrigerated conditions is ex- 

 plained. Total numbers of bacteria, the changing 

 makeup of bacterial populations, and organoleptic 

 grades are given for pink, white, and brown shrimps 

 through 14 days of iced storage. The effects of 

 thorough washing are contrasted to those of average 

 washing and the superior quality of well-washed 

 shrimp in the second week of iced storage is shown 

 by lower bacterial counts and the prolongation of 

 grade. Practical recommendations, based upon ex- 

 perimental observations or reports in the literature, 

 are offered. A series of photomicrographs show- 

 how the tissues of shrimps of all three species dis- 

 integrate in much the same way during 14 days of 

 iced storage. A selection of suggested references 

 for additional reading is provided. 



285. Hypocholesterolemic effects of marine 

 oils. By James J. Peifer. April 1968, 16 pp.. 

 tables 40 and 43. 



(No abstract.) 



286. Commercial fisheries federal aid to states. 

 By H. E. Crowther. February 1968, 35 pp., 

 53 photographs. 



(No abstract.) 



287. Report of the Bureau of Commercial Fish- 

 eries Biological Laboratory. Beaufort, N.C. 

 For the fiscal year ending June 30, 1967. By 

 Kenneth A. Henry and Joseph H. Kutkuhn. 

 June 1968, 22 pp., 17 figs., 9 tables. 



ABSTRACT 

 Results of biological research in the Anadromous 

 Fish, Blue Crab, and Menhaden Programs are dis- 

 cussed. Major topics include abundance, distribu- 



tion, and survival of blue crab and menhaden larvae, 

 juveniles, and adults; results of menhaden tagging 

 studies; and details of the 19fi6 menhaden fishery. 

 Other activities of the laboratory staff, and publi- 

 cation for Fiscal Year 1966, are listed. 



288. The Atlantic coast surf clam — with a par- 

 tial bibliography. By Robert M. Yancey and 

 Walter R. Welch. June 1968, 14 pp., 7 figs., 

 1 table. 



ABSTRACT 



The surf clam, Spinula solidissima solidissima 

 (Dillwyn), supports an important commercial fish- 

 ery along the coasts of the Middle Atlantic States. 

 The major portion of the catch has been taken off 

 New Jersey since 1949. Surf clam fishing vessels, 

 equipped with hydraulic jet dredges, take the clams 

 from depths of 100 feet or less and land them the 

 same day. Most of the catch is processed for use 

 as food; a minor portion is used as bait for fish. 

 The total catch in 1965 was 44.1 million pounds of 

 meat. 



Surf clams are found in waters of oceanic salinity 

 and sand or gravel bottoms from the low-tide to 

 depths of 480 feet. They range from the Gulf of 

 Saint Lawrence to Cape Hatteras, N.C. The sexes 

 are separate. Spawning usually occurs twice a 

 year. Eggs, under experimental conditions, failed 

 to develop in salinities below 23 parts per thousand. 

 Young clams may reach a length of 1% inches in 

 1 year. Mature clams are commonly 6 to 7 inches 

 long. Surf clams are very abundant in some areas. 

 Populations of 1 to 2 million juvenile clams per 

 mile of beach have been found at Wallops Island, 

 Va., and Sandy Hook, N.J. As many as 5 million 

 mature clams per mile of beach have been washed 

 up on Long Island, N.Y., by a storm. 



289. Annual Report of the Bureau of Com- 

 mercial Fisheries Radiobiological Laboratory 

 Beaufort, N.C. For the fiscal year ending 

 June 30, 1967. By T. R. Rice. February 1968, 

 45 pp., 26 figs., 18 tables. 



ABSTRACT 

 Research activities included studies in estuarine 

 ecology, biogeochemistry, pollution, and radiation 

 effects. 



290. Report of the Bureau of Commercial Fish- 

 eries Biological Laboratory St. Petersburg 

 Beach, Florida fiscal year 1967. By James 

 E. Sykes. June 1968, 17 pp., 17 figs., 1 table. 



ABSTRACT 

 The major goals of the Laboratory are to explore 

 the relatively unknown scope of biological produc- 

 tivity in the coastal zone of the eastern Gulf of 

 Mexico, to measure the effect of changes in that 

 zone, and to develop methods of increasing estu- 

 arine fishery resources. The report describes cur- 



