Tahitian melon squash, neck pumpkin, and Pa Dutch Crookneck are all C moschata in the butternut group. They are at least very similar and I expect suspect vendors are using the names interchangably.

Thank you. I share your suspicions. :-)

I like/prefer (taste) C. moschata butternut types over other types except for maybe green striped cushaw, which I've loved since my earliest memories.

Anyhoo, I was first introduced to the moschatas by growing the Tahiti squash, then we switched to Waltham butternut, and this year we grew Burpee Butterbush for the first time.

I have wondered the same thing but have not grown either. I was wondering if tahitian might be a bigger version? PA dutch crookneck and neck pumpkin are the same, I believe.