We describe the isolation of lambdafus2, which carries bacterial DNA from the str-spc region of the Escherichia coli chromosome. Genes for 27 ribosomal proteins were found on the genome of this transducing phage by identifying the ribosomal proteins whose synthesis was stimulated after infection of UV-irradiated bacteria. These were genes for S3, S4, S5, S7, S8, S10, S11, S12, S13, S14, S17, S19, L2, L3, L4, L5, L6, L14, L15, L16, L17, L18, L22 L23, L24, L29, and L30. Subsets of these genes were identified on the genomes of the phages lambdaspc1, lambdaspc2-delta 9, and lambdaspc2-delta16, all of which carry parts of the bacterial DNA present on lambdafus2. From the known structures of these phage genomes, it has been possible to determine the relative order of many of these genes on the lambdafus2 genome and thus on the E. coli chromosome. Our evidence also suggests that the genes for S3, S17, S19, L2, L4, L16, L22, L23, and L29 are part of a single transcription unit. These results, along with the observations described in the previous and accompanying papers, indicate that the ribosomal protein genes on lambdafus2 are organized into at least four transcription units.