A couple days ago I found some old Diatrypella fruitbodies that had Dialonectria perithechia growing on them. The Diatrypellas were growing on a thin Betula branch that was attached to a fallen tree. There were spores to be found of both species, but unfortunately these were rather old fruitbodies, so there were no asci to be found.

Diatrypella spores:

(5) 5.6 - 6.2 (6.5) × (1.2) 1.24 - 1.7 µm
Q = (3.4) 3.41 - 4.6 (5.2) ; N = 10
Me = 5.9 × 1.5 µm ; Qe = 4

Dialonectria spores:

(7.6) 7.64 - 9.47 (9.5) × 3.9 - 4.2 µm
Q = 2 - 2.3 ; N = 5
Me = 8.6 × 4 µm ; Qe = 2.1

I suspect this might be a case of Dialonectria episphaeria growing on Diatrypella favacea, although the spores are maybe a bit small for both species. 

Is this data enough to say anything with certainty, or are there other possibilities?