Grammar, Usage / Legend / Subtitles... description of images in texts. [2]

Hey there,
I need to know what's the right word when talking about the description of images in texts, as the ones seen in books or magazines. Are they called legens? Subtitles? Is there any other option?

Moreover, I need help to complete this phrase: "The images shall also be inserted in the text, juntamente com suas legendas". I don't find the right word in English for juntamente, which means something like together or maybe with. What would be the right expression in this case?

Regards,
Sara

Grammar, Usage / Magazine's periodicity - the correct term? [4]

I would like to know what's the correct term for magazines that are published three times a year. For example, I know that the term for the ones published four times a year is "quarterly", and the ones published every month are called "monthly" etc. What about magazines or periodicals published every four months? The word used in portuguese is "quadrimestral", but I cannot find the right translation! Could anyone help me with urgency, please?

Regards,
Sara Grünhagen - Brazil