142 



in both sexes. All the pereon somites are free. The head is high and short. 

 The eyes are inconspicuous. Antennae I are strong and long, projecting 

 forward; in females they are equal to 2-4, and in males 5-7 somites 

 of the pereon; the peduncle is two-segmented; the proximal segment of 

 the flagellum is narrow; the three distal segments in comparison with 

 other Physosomata are well developed. Antennae II in males are thin, 

 almost not shorter, or longer than antennae I; in females they are short, 

 rudimentary. The mandibles lack a palp, have a narrow cutting edge and 

 an accessory plate. The outer lobe of maxillae II exhibits a tendency 

 toward reduction; it is narrower and shorter than the inner lobe. The 

 outer lobes of the maxillipeds are large, oval; the inner lobes are split 

 almost from the base. The coxal plates are free. In pereopods I and II 

 the 5th segment is almost not broadened distally. In pereopods V the 

 2nd segment has smooth margins. Pereopods V-VII may have retractile 

 claws. The rami of the uropods are free. The gills are located under 

 somites II-VI. 



The family Proscinidae includes rare deepwater species; their sex- 

 and age-related dimorphism is poorly studied; possibly, with the avail- 

 abiHty of new material, this family will require significant revision. 



The family includes two genera. 



KEY TO GENERA OF FAMILY PROSCINIDAE 



1 . Inner lobes of maxillipeds broad, weakly tapering and with pubescence 

 only in distal part. Pereopods V-VII without spoon-shaped structure 

 at tip of 6th segment; claws on these pereopods nonretractile ...... 



1 . Proscina Steph. and Pirl. 



— Inner lobes of maxillipeds strongly tapering distally and with one 

 strong apical seta. Pereopods V-VII with spoon-shaped a structure at 



tip of 6th segment; claws on these pereopods retractile 



2. Mimoscina Pirl. 



1. Genus Proscina Stephensen and Pirlot, 1931 



Stephensen and Pirlot, 1931: 343. 



Crustaceans of medium size. The integument is thin. The head is 

 almost as high as somite I of the pereon. The proximal segment of the 

 flagellum of antennae I is long and strong, conical, and structured as in 

 the genus Mimonectes; the 1st and 2nd distal segments are short and 

 broad; the 3rd segment is longer than both the preceding segments. 

 Antennae II in males are thin, multisegmented, and roughly the same 

 length as antennae I; in females they are shorter, sometimes reduced to 

 an acicular appendage. The mandibles have a well-developed (in the left 

 mandible) accessory plate; its length is equal to that of the cutting edge. 



