I had tried there but not being able to speak German and using Google translate, I got lost. So, we appreciate the kindness of strangers ("Ken S") who took the time to post it for us.
He also posted further information:
"The cemetery is Plaine-de-Walsch. According to the regimental history on August 19 his company advanced toward a village called Sitifort which is about 3 km to the SE of Plaine-de-Walsch and were fired upon by the French. The regimental history states that among the killed were a Lt. Thelen and Feldwebel (ie. a Sergeant) Marienfeld. According to Volksbund there was a Lt. Leonard Thelen who died August 20 and a Vizefeldwebel Marienfeld who died August 21. Both are said to be in unmarked graves, possibly in Plaine-de-Walsch. That shows that in general there appear to have been discrepancies in the dating for casualties at this time and location, also that the burial for members of the regiment killed during this time would (likely) have been Plaine-de-Walsch.
In terms of August Storm's birthplace, there is an online record of the village's war memorial as well as a list of names (Namensregister). Since he does not appear on the list, he likely was resident elsewhere. Fusilier-Regiment Nr. 40 was associated with (but not garrisoned in) a territory called Hohenzollern in southern Germany (around the city of Sigmaringen). After the war, the territory compiled an extensive honor roll listing most from the territory who served in the war, c. 14,000 names. If he was resident there, he will likely be listed; unfortunately, there is no index, and the men are listed by town/village which makes searching a little difficult if you don't know what community they're from. Also I have a book about the garrison of Rastatt where the regiment was located in peacetime. It also has an honor roll."