• The covering of the mucosa is a simple columnar epithelium, invaginated into gastric pits, into which many long tubular gastric glands empty their secretions. The muscularis mucosae is the smooth muscle layer forming the deep border of the mucosa.
• The submucosa—thicker areas of this layer are the bases of rugae (which can also be seen without the microscope).
• The muscularis is very thick in the stomach; you may be able to distinguish three (not just two) layers.

Below are some links to several images detailing the microscopic elements you should be able to identify on this STOMACH slide.

• Gastric pits and gastric glands
• Simple columnar epithelium
• Muscularis and serosal surface

See this slide with the virtual microscope

I don't see the virtual slide, I must need the download.