Sentence:  Snakes are quite frequently depicted on <WSD>sowei</WSD> masks and it is possible that they are related to Sande lore or ritual practices, since snakes are found in rivers where the Sande spirit lives and where a number of important ceremonies take place. 
Meaning of the word marked with <WSD> tags:  A guardian spirit of a Sande society of the Mende, who is represented by a special helmet-like mask.