It is well known in Hyborian lore that Conan the Cimmerian went by the name "Amra" [the lion] when he was a pirate. From 1959 to 1982, there was a magazine named Amra—which grew from a fanzine to a professional fantasy magazine—about Conan, as well as heroic fantasy more generally. And lots of later authors who have written about Conan's piratical career have use the name.
However—and quite peculiarly, it seems to me—Robert E. Howard only mentions the name "Amra" as Conan's former pirate alias in two stories: "The Scarlet Citadel," the second story featuring Conan, and The Hour of the Dragon, the second to last. Both of these stories take place in the final phase of Conan's career, when he is king of Aquilonia. The first time the name appears, it is clearly identified as the king's former pirate alias:
"Long have I wished to meet you, Amra," the black gave Conan the name—Amra, the Lion—by which the Cimmerian had been known to the Kushites in his piratical days.
However, in between the "The Scarlet Citadel" and The Hour of the Dragon, the stories Howard wrote never mention the name "Amra." This includes multiple stories that detail parts of Conan's pirate career: "The Pool of the Black One," "Iron Shadows in the Moon," "Queen of the Black Coast," and "The Black Stranger" (in publication order; "The Black Stranger" was written before The Hour of the Dragon but was not published until after the author's death).
Of these, "Queen of the Black Coast" is the only one in which Conan's piracy takes place predominantly off the Kushite coast, with an African crew. Yet Conan is never referred to as "Amra," even in dialogue. Bêlit just calls him "Conan":
"My lover, I believe there is a city somewhere on that river. I have heard tales of giant towers and walls glimpsed afar off by sailors who dared go part-way up the river. We fear nothing: Conan, let us go and sack that city."
...
"Mystery and terror are about us, Conan, and we glide into the realm of horror and death," she said. "Are you afraid?"
A shrug of his mailed shoulders was his only answer.
"I am not afraid either," she said meditatively. "I was never afraid. I have looked into the naked fangs of Death too often. Conan, do you fear the gods?"
...
"There is life beyond death, I know, and I know this, too, Conan of Cimmeria—" she rose lithely to her knees and caught him in a pantherish embrace—"my love is stronger than any death! I have lain in your arms, panting with the violence of our love; you have held and crushed and conquered me, drawing my soul to your lips with the fierceness of your bruising kisses. My heart is welded to your heart, my soul is part of your soul! Were I still in death and you fighting for life, I would come back from the abyss to aid you – aye, whether my spirit floated with the purple sails on the crystal sea of paradise, or writhed in the molten flames of hell! I am yours, and all the gods and all their eternities shall not sever us!"
Is there a known reason for this apparent inconsistency? Did Howard forget about the pirate name, "Amra" that he had invented for Conan early on—only to rediscover it when he decided to write more about Conan's time as king of Aquilonia?