Anne McCaffrey's pegasus series is predated by its prequels The Rowan, Damia and a few other books in that series. Tower and the Hive comes much later in the story line.
I think we can probably thank the marketroids for the confusion, but the Damia books came to be lumped together as 'Tower and the Hive series' (with the original definite article missed off) around about the fourth book (Lyon's Pride) and rather confusingly finished with a book entitled 'The Tower and The Hive'. Around about the same time the Pegasus books started being grouped together under the heading of 'Talent Series' and more recent books have listed Damia et al as 'Tower and the Hive Sequence' rather than series.
Irrespective of the labelling, all are well worth reading