109 



a well defined concaved palmar edge, dactylus strong and curved. Pereiopnda 

 comparatively slender, basal joint of the 3 posterior pairs large and laminar. 

 Branchial lamellae simple. Last pair of nropoda much larger than in Onesi- 

 WHX and reaching considerably beyond the preceding pair, both rami partly 

 setous on the inner 'edge. Telson oblong and deeply cleft. 



Eemarl-s. The present new genus is intermediate in character lie 

 tween the genera Onesimm and Anouyx, resembling the former in the general 

 form of the body, the latter in the structure of the oral parts and caudal 

 appendages. From both it is markedly distinguished by the peculiar power- 

 ful structure of the posterior gnathopoda, a character which has given rise 

 to the generic title here proposed. It may be observed that two of 

 the species described by Dr. Hansen from the Kara Sea and referred by him 

 to the genus Onesimus exhibit a quite similar structure of these limbs, a 

 fact which would seem to indicate a closer relation to the present genus. 



49. Chironesimus Debruynii, (Hoek). 



(PL 37, fig. 2). 



Anonyx Debnnjmi, Hoek, Die Crustaceen gesammelt wiihrend (lev Fahrten der Willom Ba. 

 rents*. Niederl. Arch, fur Zoologt. Suppl. Bd. 1, p. 44, PI. Ill, fig, 30. 



Body rather robust and tumid, with broadly rounded back. Cephabm 

 about the length of the 1st segment of mesosome, lateral corners somewhat 

 produced and narrowly rounded at the tip. Anterior coxal plates fully twi et- 

 as deep as the body; 1st pair scarcely expanded below ; 4th pair deeply emargi- 

 natecl posteriorly and forming below the emargination a rather large angular 

 expansion; 5th pair not very large, more broad than deep. Last pair of epi- 

 meral plates of metasome produced at the lateral corners to an acute trian- 

 gular, somewhat upturned lobe. First segment of urosome but slightly de- 

 pressed dorsally. Eyes oblong oval, a little broader below, pigment red. 

 Superior antennae about the length of the cephalon and the 2 first segments 

 of mesosome combined; 1st joint of the peduncle very large and thick; flagel- 

 lum exceeding the peduncle by about V* of its length and composed of about 

 11 articulations, the 1st of which equals in length the 3 succeeding ones 

 combined; accessory appendage about half the length of the flagellum and 

 6-articulate, 1st joint being very large and somewhat expanded. Inferior anl ennte 

 a little longer than the superior, the 2 outer peduncular joints nearly of 

 uniform length, flagellum composed of about IT) articulations. Anterior gna- 

 thopoda with the propodos scarcely as long as the carpus and much narrower, 

 palmar edge slightly concaved and defined below almost rectangularly. 



15 Crustacea. 



