Comollo means Little Jacob, and has five variants, one of which is Jacobellis.
According to the Dizionario ragionato dei cognomi (Annotated Dictionary of Surnames) by Frangipane, Comollo is the truncated and endearing form from the proper name Giacomo (Jacob): Giacomocomollo. It is less probable that it is a toponimic from Como, because there are many similar surnames that maintain the original stem, such as: Giacomino, Giacomelli, Giacomolli, Giacometti, Jacobellis, Jacobacci and so on. 
Comollo Little Jacob (truncated) Comolli, Comelli, Comino, Giacomelli, Giacometti, Giacomino, Jacobelli, Jacobellis and similar 
