τῇ αυρίον (accent on the penultima)

Greek Learning Greek
1

I am going through Sidgwick’s work, found here: http://www.textkit.com/learn/ID/167/author_id/66/
On page 28, paragraph 37, related to the use of the dative, he supplies the example:

Τῆ ἀυρἰον.

Much as in Modern Greek την επαύριο this stands, I believe for Τῆ ἀυρἰον ἡμέρᾳ.

But why is the accent not on the first syllable? Checking Liddell Scott, I only see accents on the first syllable: http://www.perseus.tufts.edu/hopper/morph?l=au%2Frion&la=greek#Perseus:text:1999.04.0057:entry=au)/rion-contents

2

I expect it’s just a typo.