Is saw seashells at the an of alliteration or onomatopoeia?

Here's why:

* Alliteration is the repetition of the same consonant sound at the beginning of words that are close together. In this case, the "s" sound is repeated in "saw" and "seashells."

* Onomatopoeia is the use of words that imitate the sounds they represent (like "buzz," "crash," or "meow"). There's no sound imitation in "saw seashells."