Glands in the head capsule of coccinellid beetles with a discussion on some aspects of gnathal glands

Glands are classified by structure as multicellular complex acinose, multicellular simple tubular, and unicellular; by position as general, hypodermal, ocular, anternnal, intra‐mandibular, mandibular, mandibulo‐maxillary, maxillary, intra‐cardonal and labial. Some open outside the extra‐oral cavity. They are supposed to be offensive in function. The segmental origin of the gnathial is doubtful.