This is a vintage lot of paperback Star Trek books based on the original series dated 1970 - 1981. Numbers 1-4, 6-13, &15, 16 are included in the lot. The lot is missing 5 &14. 

Star Trek Adventures (1970–1981)
Novels based on The Original Series.[a] Bantam never applied an official series name to the novels, instead marketing each volume as a new or original "Star Trek Adventure". Library catalogs and booksellers numbered the series in publication order, including Mudd's Angels and The New Voyages. In 1993, the series was reprinted by Titan Books as Star Trek Adventures with different number stamps. The reprint series name has been retroactively applied to Bantam's releases fans and by book discovery websites such as LibraryThing.

#1    Spock Must Die!   James Blish,  8th printing, February 1972,  Has original owner name inside of front cover.

2    The New Voyages (short story collection) Sondra Marshak and Myrna Culbreath, 8th printing, Feb. 1979

3    Spock, Messiah!         Theodore Cogswell and Charles A. Spano Jr.      September 1976         

4    The Price of the Phoenix        Sondra Marshak and Myrna Culbreath      July 1977, 2nd printing        

     #5 missing

6    The New Voyages 2 (short story collection) Sondra Marshak and Myrna Culbreath, January 1978, 4th printing, tanned pages       

7    Mudd's Angels [III] (short story collection)   J. A. Lawrence            May 1978, tanned pages        

8    Vulcan!            Kathleen Sky  September 1978, 2nd printing, tanned pages  

9    The Starless World     Gordon Eklund           November 1978         

10  Trek to Madworld       Stephen Goldin           2nd printing 1980        

11  World Without End    Joe Haldeman February 1979

12  The Fate of the Phoenix         Sondra Marshak and Myrna Culbreath, May 1979, 2nd printing, crease on spine          

13  Devil World    Gordon Eklund           November 1979

    #14 missing  

15  The Galactic Whirlpool          David Gerrold,            October 198, 1st ed    

16  Death's Angel Kathleen Sky  April 1981, 1st ed, minor tear on lower spine