A taxonomic review of the two genera of the family Alvinocarididae (Decapoda: Caridea), Rimicaris Williams and Rona, 1986 and Chorocaris Martin and Hessler 1990 , is presented based on study of type materials and/or supplemental material from recent collections. Two species of Rimicaris, R. exoculata Williams and Rona 1986 and R. kairei Watabe and Hashimoto 2002, and three species of Chorocaris, C. chacei Williams and Rona 1986, C. vandoverae Martin and Hessler 1990, and C. paulexa Martin and

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... ank 2005, are recognized. All species are exclusively associated with deep-water hydrothermal community. Close relationship between the two genera is confirmed by morphological characters, but the monophyly of Chorocaris is not corroborated. An examination of a good series of material from the Mid-Atlantic Ridge shows that juveniles of Rimicaris exoculata can be arranged in four sequential ontogenetic stages based on morphology. A dramatic change occurs at the size of 7.0 to 9.0 mm in the carapace length. The synonymies of Iorania concordia Vereshchaka 1996 and Rimicaris aurantiaca Martin, Signorovitch & Patel 1997 with Rimicaris exoculata, indicated from molecular evidence by Shank et al. (1998) , are confirmed. Morphological differences between R. exoculata and R. kairei and those among C. chacei, C. vandoverae, and C. paulexa, are reassessed.