| Issue | #42 |
| Published | March 1968 |
| Cover Price | 0.12 |
| Pages | 36 |
| Editing | Stan Lee |
| Notes | This issue includes the statement of ownership, management, and circulation. |
| Characters | The X-Men [Angel; Beast; Cyclops; Iceman; Marvel Girl]; Changeling |
| Genre | superhero |
| Pencils | John Buscema; John Verpoorten ? (retouches) |
| Inks | John Buscema; John Verpoorten ? (retouches) |
| Notes | Unaltered cover published in X-Men # 90. This issue includes the statement of ownership, management, and circulation. |
| Reprinted | in X-Men (Marvel, 1963 series) #90 |
| Characters | The X-Men (Angel, Beast, Cyclops, Iceman, Marvel Girl); V: Grotesk; GS: The Changeling (D; as Prof. X) |
| Genre | superhero |
| Script | Roy Thomas |
| Pencils | Don Heck |
| Inks | George Tuska |
| Letters | Sam Rosen |
| Reprinted | in X-Men (Marvel, 1963 series) #90; in Marvel Special (Marvel Italia, 1994 series) #15 |
| Characters | O: Cyclops (conclusion); V: Living Diamond (D); Professor X; |
| Genre | superhero |
| Script | Roy Thomas |
| Pencils | Werner Roth |
| Inks | Herb Trimpe |
| Letters | Al Kurzrok |
| Reprinted | in Amazing Adventures (Marvel, 1979 series) #5 (April 1980); in Marvel Special (Marvel Italia, 1994 series) #4 |