216 Amphipoda and Isopoda 



Eyes absent. 



Superior antennce with a three-jointed peduncle. 



Inferior antenna? with a fine-jointed peduncle, flagellum greatly 

 elongated and many-jointed. 



First three pairs of legs with the propodus smooth, cylindrical, not 

 expanded ; dactylns extremely strong, hooked, sharply curved in the 

 centre, and terminating in a darkened, very sharp point. 



Last four pairs of legs moderately slender, successively increasing 

 in length, ischium provided with a posterior lobe ; dactylus hook- 

 shaped. 



Pleopods consisting throughout of a pair of broad lamellae, provided 

 with setae all round. 



Telson very small, leaving the pleopods quite uncovered, lingui- 

 f orm in shape, unarmed. 



Uropods uniramous, consisting of short basal joint articulated 

 ventrally to the telson, and a terminal very long, stout spinous seta, 

 provided with numerous fine plumose setae. 



This remarkable new genus anterioi'ly resembles the genus 

 Syscenus, Harger ; but the form of the telson, the uncovered pleopods, 

 and the unique and rather anomalous form of the uropods at once 

 separates it from all other known members, not only of the family 

 jEgidce, but of the whole tribe Flabellifera. 



XENURiEGA Ptiloceea, gen. et sp. nov. 



Locality.— Lat. 36° 18' N., Long. 23° 53' W., June, 1904. Closing- 

 net, 400 fathoms. 



Body (Plate V., Fig. 1) rather slender and slightly depressed, 

 about four times as long as the greatest width of the mesosome ; 

 cephalon very small and triangular in shape, much narrower than the 

 first segment of the mesosome ; metasome rather more than one-third 

 of the total length of the body, much narrower than the mesosome, 

 the segments successively narrowing towards the posterior end. 



Mesosome (Plate V., Fig. 1) with the first segment larger than 

 any of the succeeding ones, the remaining ones more or less subequal 



