234 BULLETIN 166, UNITED STATES NATIONAL MUSEUM 



Subfamily Matutinae Alcock 



Matutidae Dana, United States Exploring Expedition, Crustacea, pt. 1, p. 394, 



1852; pt. 2, p. 1427, 1853. 

 Matutinae Alcock, Journ. Asiatic Soc. Bengal, vol. 65, p. 139, 1898. 



Merus of external maxillipeds elongate and acute, entirely conceal- 

 ing the palp in repose. Legs natatorial. (Alcock). 



Genus HEPATUS Latreille 



Hepatus Latreille, Histoire naturelle . . . des Crustaces, vol. 3, p. 22, 1802 



[type, H. princeps (Herbst) ■=//. angustata Fabricius). 

 Hepathus Lamarck, Histoire naturelle des animaux sans vert^bres, vol. 5, p. 267, 



1818 (type H. calappoides Lamarck). 

 Hepatulus^* Fowler, Ann. Rept. New Jersey State Mus., 1911, p. 590, 1912 



(type, H. fasciatus Latreille) . 



Carapace broad, convex, regularly arcuate in front, strongly narrow- 

 ing behind; hepatic regions very large, branchial regions very small. 

 Front narrow, straight or nearly so, rather prominent, and situated 

 above the level of the lateral border of carapace, which is prolonged 

 beneath the orbits to join the margin of buccal cavity. Orbits small, 

 circular, on a level with front. Antennulae very obUque. Antennae 

 at inner angle of orbit. Buccal cavity very narrow forward and tri- 

 angular, extending as far as level of lower border of orbits and entirely 

 covered by outer maxillipeds, of which the merus is triangular and 

 has straight inner margin, under which are concealed the following 

 segments. Chelipeds strong, and when flexed fit closely against lower 

 surface of body. Hands with a superior crest, fingers inclined a httle 

 downward and inward. Ambulatory legs smooth, unarmed. 



Georgia to Brazil; west and south Africa; East Indies; west Mexico 

 to Chile. 



KEY TO THE SPECIES OF THE GENUS HEPATUS 



A'. Sixth segment of male abdomen smooth, 



B'. Front advanced beyond line of suborbital cavities.^s 



C». Carapace covered with small spots. Front bidentate--princeps(p. 235) 

 C2. Carapace covered with large spots. Front truncate. epheliticus(p. 238) 

 B2. Front not advanced beyond line of suborbital cavities. Cara- 

 pace covered with narrow arcuate stripes of color. Two 

 large tubercles on fourth abdominal segment of male.kossmanni (p. 239) 

 A^ Sixth segment of male abdomen not entirely smooth. 



B'. Front scarcely advanced beyond line of suborbital cavities. 

 No teeth on posterior margin. Sixth segment of male 



abdomen with a median terminal tubercle chiliensis (p. 244) 



B2. Front advanced; suborbital cavities not visible from above. 

 A prominent tooth near either end of posterolateral 

 margin. Segments 1-6 of male abdomen tuberculate-.lineatus (p. 246) 



2< Substituted for Hepatus Latreille, 1802, a name preoccupied by Gronow, 1763, for a genus of fishes. In 

 1925 Gronow's name was rejected by the International Commission on Zoological Nomenclature (Smith- 

 sonian Misc. Coll., vol. 73, no. 3, opinion 89). 



" In pi. 70, fig. 1, the carapace of H. princeps is tipped backward. 



