You can find them at the usual suspects, NARA, FHL and Ancestry.com
FHL Film NARA Film Dates
0419918 M277-24 Apr. 1--May 19, 1848
0419919 M277-25 May 20--July 10, 1848
0419920 M277-26 July 11--Sept. 30, 1848
0419921 M277-27 Oct. 2--Dec. 29, 1848
Ancestry:
http://search.ancestry.com/search/db.aspx?dbid=8745In all cases, there are no lists for Jan 1 - Mar 31.
Mass. Archives appears to have transcriptions of the missing dates.
http://www.sec.state.ma.us/ArchivesSearch/Passengermanifest....