CAMBRIDGE, Mass. - The Trinity College varsity eight finishes 16th in a field 40 boats in the Collegiate Eights race at the Head of the Charles Regatta this afternoon on the Charles River.  The Bantam crew posted a time of 18:13.201 to place 1.3 seconds behind Williams' second-varsity eight and .06 faster than 17th-place Middlebury.  Mercyhurst won the team title at 17:16/794.  In the Collegiate Fours race, Trinity's  entry came in 23th of 32 teams with a time of 21:07.483.  Th Bantams will close the fall at the Head of the Fish Regatta in Saratoga Springs, N.Y.