Ithenite

The Ithenites are a race that, according to temporal agent Daniels, joined the Federation some time before the 26th century. 

Background
The Ithenites had probably made first contact with Earth sometime prior to 2154, since it is unlikely that Daniels would deliberately contaminate the timeline further by mentioning an alien race Archer hadn't heard of.

An unshot scene from the script included a character called "Karash", an Ithanite [sic] ambassador attending the conference on Earth. He is described as a diminutive, copper-skinned alien. This was supposed to be the same alien species as seen in.

Ithenit イセナイト Ithenite Iteniter