Found on dung of fallow deer. Out of 24 pellets only one showed these species. Species were found in combination with Sporormiella grandispora.

At first becasuse of its long neck I was thinking of Sporormiella longispora/longisporiopsis (forum nr 65389) but spore measurements revealed that spores were much smaller.
Measurements were within range of Sporormiella dubia (forum nr 23372) but S. dubia does not develope a long hyaline neck and spore cells for the latter are equal in length and form.
This species however has at least one conical end cell, two cylindrical cells with one being an endcell and one bulbous cell. Asci sometimes contain three to four spores.

Perithecia: immersed with only the neck visiblle, subglobose to globos 209-300x173-296 um in diam. Dark brown to nearly black. When not fully mature no neck is visible but it develops a long hyaline neck up to 320x87 um having a top covered with short longitudinal cells.

Peridium consists three layers of cells whilst the neck is covered with two layers of cells, top of the neck is covered with small longitudinal cells

Asci: 8 or occasionaly 4 spored, cylindrical-clavate, rounded at the top, gradually contracted below into a peristend stipe measuring 17.5-23 um in length. Stipe can extend to 109-139 um.
Asci with 8 spores measure 130-150x28-30.5 um, asci with 4 spores measure 125-130x21-24 um. 

Paraphyses: abundant, filiform, septate, filled with particles 2.4-2.9 um, expanding when more mature to 3.6-4.5 um.

Ascospores: obliquely two tri-seriate sets at the top followed by one bi-seriate set below when asci expand in length spores are longitudinal positioned in 4 bi-serial sets 4-celled, cells can change is size and shape whereby the 2nd cell is prodominantly bulbous, 46.5-51.5x7.5-10.5 um, straight or curved, light brown when young, becoming dark brown when mature, septa transverse, constrictions at septa deep, cells not easy to separate; germ slit parallel and in one line with all 4 cells, gelatinous sheath hyaline and very small.

I do have my doubts about S. dubia because of the differences between the description of  S. dubia and the measureents of this species.

The last two photos show a perithecia developing a long hyaline neck.

Regards,

Joop