Australian publisher Cohesion Press is open for novella submissions of 10,000 to 40,000 words in the following genres:
Military Sci-fi or Horror
Post Apocalyptic Horror (preferably not zombies)
Plot Driven Horror (includes all the punk sub-genres)
Young Adult (I know, not a genre :) )
They pay 80% royalties on the net profits for ebooks. 50% for print. The deadline is October 2. You can find all the details here.
They also have an anthology call listed titled "Snafu". This is a limited call for three or four stories only as most of the anthology has already been solicited. They need military sci-fi stories of 3000 to 7000 words, payment is 3cents a word. Details for this can be found under the Submission link at the top of the page.