In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Cerebellar volume for the patient group ranged between 67 . 66 and 131 . 08 ml ( mean 108 . 9 ml ) .
### Output Text:
Cerebellar volume for the patient group ranged between 67 . 66 and 131 . 08 ml ( mean 108 . 9 ml ) . 