Help with dative of possession

[pmda]

I'm struggling with something and I'm wondering if anyone can help.

In Orberg's Exercitia Latina Ch XII Exercitum 14. No.11 There is the exercise (fill in the blanks)

11. Cornelius equum formos___________ habet quam Iulius; Cornelius dominus equi formos_______ est.

Now I put in here the following:

11. Cornelius equum formosiorem habet quam Iulius; Cornelius dominus equi formosiores est.

Isn't 'Equi' here Nom. Pl. and wouldnt' it take formosiores.

Orberg gives the correct answer as formosioris - which I can't figure out.... can anyone advise?

[furrykef]

"Equī" here is genitive singular, modifying "dominus"; "fōrmōsiōris" is genitive singular to match. "Cornelius is the man with [lit. 'of'] the prettier horse."

By the way, I'm confused a bit by the topic title, since I see no dative here...

[pmda]

What can I say? I suppose learning on your own is like rowing across the Atlantic on your own. There is a danger that you'll start confusing seagulls for enemy fighters...Thanks. It was early in the morning - total loss of perspective - mental block.....that's why this forum is wonderful - thanks. Why did I put dative of possession...? same problem. Once you replied it was totally obvious...