[Mr_Chicken]

perhaps something like this: Allen's Halloween Page: Grim Reaper Costume

 

[Zombie Machairodont]

Mr._Chicken: Oh man, those are cool! I recall having a plastic skeleton arm that had semi-functional fingers that would flex when you pulled on the corresponding lever inside the glove area, but this is really quite beautiful. I may have to eventually study his photo and try something like that myself!

bhub: If you are looking for something more along the lines of gloves, there is quite an assortment out there, and I suppose it would depend on how much you are willing to pay. There are some cheaper gloves that aren't just the skeletal fingers sewn onto a black glove, but it seems like a lot of these may have open or less-than-realistic palms since most seem to really hide the hand's underside:
Bone Hands with Gauze - Accessories & Makeup

I know I've seen some particularly creepy skeletal gloves that have very long fingers to make the proportions right (so that the part where your hand doesn't look too thick). If I come across some, I'll post a picture and link here ... that is, if someone doesn't beat me to it.

 

[Zombie Machairodont]

These aren't quite what I was looking for, but at least they show a fairly nice sculpting job on the palm, and they are complete gloves.

Deluxe Skeleton Hands Halloween Gloves
Still, they probably don't meet your desire for realism that turned you off of gloves for the costume in the first place.

I also tried to look for projects or tutorials like the one shown in Mr_Chicken's post, but came up empty handed. The idea of a skeletal hand that moves with your own through artificial tendons seems a logical-enough idea and I can also think of placing the "tendons" inside of a flexible jointed structure. I'm not sure if you are looking to make your own, so I won't go into detail here unless you are interested (plus, I've never actually made the design I'm thinking of, so there could be a number of inherent problems with it).

 

[skullboy]

Halloween Exspress had some decent looking ones in the store yesterday.

 

[the dogman]

The link provided by Mr. Chicken is the same idea I was thinking when I read your post.

I found and instructable that may be able to help you work out how to make that style of hand using some bucky hands or something of the like.

Simple Animatronics (robotic hand)

Hope this helps you out!

 

[dwdoadrummer]

Hands, Ghostly Bones - Accessories & Makeup

i would go with these, and it says the underside is open, you can do a few things....

where a pair of black latex gloves uneath, so you wont notice skin

get those gloves with the skeleton fingers stiched on and where them reversed,

or simply paint the palsm of ur hands white, or have someone else paint them, and do the darker details around the knuckles and put in the cracks in th hands and stuff

 

[red_scare]

does your robe extend to your wrist? you could paint a skeleton on your hand with acrylic paint maybe... the only thing is if you sweat it might run!