Trouble with Whelks

[Jeff D]

These were seen snorkelling at Stony Beach in Woods Hole on Cape Cod.
I think the first one is a Common Whelk (Buccinum undulate), the next two perhaps a small Channeled Whelk (Busyrotypus canaliculatus) and the last one a Dog Whelk (Nucella lapels). None of these were larger than an inch and were located on a pebbly bottom in two feet of water. Can anyone confirm these ID's or suggest a different one?
Thanks again.

[paul monfils]

Pictures #1, 2 and 3 all show the common oyster drill Urosalpinx cinerea. At the left side of picture #1 are a couple of common Atlantic periwinkles, Littorina littorea. Picture #4 shows several Littorina littorea, the two at the right sitting on top of an eastern oyster, Crassostrea virginica.

[Jeff D]

Wow, I was completely clueless....Can't thank you enough Paul. It continues to be a learning experience.