Jones, Meredith L. (1974). On the Caobangiidae, a new family of the Polychaeta, with a redescription of Caobangia billeti Giard. Smithsonian Contributions to Zoology. 175: 1-55.
The type-species of Caobangia Giard, C. billeti Giard, is redescribed, primarily in terms of its setal morphology. The description of six new species of Caobangia extends the distribution of the genus from North Vietnam to Thailand, Burma, Ceylon, India, Bangladesh, Java, Sabah, Sarawak, and certain of the Philippine Islands. The genus is associated with gastropod molluscs of the families Thiaridae, Pleuroceridae, and Viviparidae, and with the bivalve family Unionidae. Detailed observations on the external morphology and the anatomy of species of Caobangia, as well as their setal structure and distribution, have contributed to the decision to erect a separate family, the Caobangiidae, for the genus. Familial characters are: the presence of neurosetal palmate hooks on the first setiger; the absence of hooks of any sort on the following thoracic setigers; the presence of two types of avicular hooks in the posterior region; and the recurving of the gut, within the body, such that the anus opens anteriorly, in the region of the second to fourth thoracic setiger. Anatomical observations on the branchial crown and its supporting skeleton, the nervous system, the nephridial ducts, and the reproductive system of these hermaphroditic, larviparous, freshwater polychaetes are reported. Further comments are made on larval morphology, settling, and metamorphosis, as well as on the molluscan associates and their habitats, and some basic questions of biological import posed by the morphology, anatomy, and development of Caobangia are propounded.