| Issue | #40 |
| Published | July-August 1958 |
| Cover Price | 0.10 USD |
| Pages | 36 |
| Editing | Julius Schwartz |
| Pencils | Gil Kane |
| Inks | Gil Kane |
| Synopsis | While visiting Danny's Uncle Ben, a western sheep rancher, Rex meets nick the sheep dog and teaches a young lamb the true meaning of being a hero. |
| Script | Robert Kanigher |
| Pencils | Gil Kane |
| Inks | Bernard Sachs |
| Synopsis | While baby sitting a kangaroo, Bobo captures two men who are wanted as witnesses by a government committee. |
| Script | John Broome |
| Pencils | Carmine Infantino |
| Inks | Carmine Infantino |
| Synopsis | In the Sahara Desert Rex becomes a member of the French Foreign Legion while helping Harold Weston find his missing brother, Peter. |
| Script | John Broome |
| Pencils | Gil Kane |
| Inks | Bernard Sachs |