Paulson, 1875
Gall crabs, coral-dwelling crabs, forming galls on branching corals or pits on reef corals, and markedly specialized owing to their commensal association. Size extremely small. Females larger than males and with posterior abdomen greatly expanded to form egg brood chamber, largely visible in dorsal view. Sexual dimorphism pronounced. Carapace narrow, generally longer than broad, often very elongate and oblong, sometimes widened anteriorly, sometimes quadrate. Dorsal surface convex, with regions faintly defined, sometimes with outlined depressions. Front usually bimarginate, more or less deflexed, generally without a central tooth. Eyes directed antero-laterally or anteriorly, sometimes nearly vertically, more or less exposed dorsally. Antennules not retractile into sockets; basal article with projections extending to or beyond eyestalks. Antennae small. Epistome weak. Mandible with cutting edge lacking processes; palp absent. Maxilla 1 consisting of undivided protopodite and exopodite; exopodite reduced, shorter than lateral margins of ischium and lacking flagellum, or absent. Third maxilliped broad; merus much smaller than ischium. Chelipeds weak. Ambulatory legs similar or not, very short and stout; merus specially broadened; dactyli short, hooked for strong adhesion. Thoracic sternum anteriorly produced in a portion separating the bases of third maxilliped. Female openings sternal. Male openings coxo-sternal. Female abdomen with three pairs of pleopods, on abdominal segments 2 to 4, the fourth being uniramous. G2 short. (Guinot 1998)
Type genus: Cryptochirus Heller, 1861.
Genera treated:
genus Cryptochirus Heller, 1861
genus Dacryomaia Kropp, 1990
genus Fizesereneia Takeda & Tamura, 1980
genus Fungicola Serène, 1966
genus Hapalocarcinus Stimpson, 1859
genus Hiroia Takeda & Tamura, 1981
genus Lithoscaptus A. Milne Edwards, 1862
genus Neotroglocarcinus Takeda & Tamura, 1980
genus Opecarcinus Kropp & Manning, 1987
genus Pseudocryptochirus Hiro, 1938
genus Pseudohapalocarcinus Fize & Serène, 1955a
genus Utinomiella Kropp & Takeda, 1988
genus Xynomaia Kropp, 1990