yes, i know these beads but dont know any local or trading name for them- and also am most intrigued by the transparent middle zone- but dont have any more information than you have-

i'm confident they are Venetian and contemporary with the other lampwork beads intended for African trade, late 19th/early 20th C.
John Picard may know more because he has studied sample cards very methodically -and Jamey too of course-

good luck with your research, and please let us know if you find out more...

They do indeed turn up on the Sick & Co sample cards amidst other Venetian made lampwork beads from the early 1900's. There are several varieties of them around.

Thank you Floor;

I have seen them on sample cards and I have three green versions of this bead in my collection. Not one of my favorite Venetian trade beads.

Sincerely
Thomas Mercer

Thank you Stefany;

So I should think of the beads as "lampwork" instead of wound beads with trailed decoration.

Sincerely
Thomas Mercer

arent they both - just not furnace-wound,,,?

Hi Thomas,

These are Venetian early 1900's African trade beads. I bought the yellows and also whites from a reliable Gambian dealer. The whites have red and blue stripes with a green central band.

Regards, Florence