I've never seen a picture of one of these. The article
says that only a few without handles have been found.
The Romans' close order and discipline made the short
gladius superior to the Gaul's long two handed swords
used with little discipline. But the short sword would
have been useless on horseback.

Spatha: The cavalry sword of the romans, between 36" - 40" in length, made from iron. The shape of the hilt is unknown to us, as only a few blades have survived. These blades can easily be confused with their Medieval counterparts, which were of approximately the same length and shape. The Roman footsoldier wielded a much shorter chopping and thrusting sword called the gladius.

This is probably a modern reproduction:

http://www.armor.com/2000/catalog/item902.html

Dear Faldage: I wonder when curved blades for cavalry
came into use. I don't know the physics involved, but
somehow more energy can be stored in a curved blade so
that the blow is more effective.
Looks like a typo in the description "linticular" I
think should be "lenticular".

A custom made spatha, of a type for an average auxillary calvary trooper. The blade is of linticular section and the hilt is made from walnut.