489 



than half its length. The flagellum of antennae II in males is folded four 

 times and the apical segment short. 



The 2nd segment of pereopods I in females is almost linear and 

 straight, in males has a sharply curved posterior margin; the 5th segment 

 is broader than the 4th; both margins of the distal process of the 5th 

 segment and the posterior margin of the 6th are denticulate. The 2nd 

 segment of pereopods II is straight and in both males and females longer 

 than in pereopods I; the structure of the distal segments is the same as 

 in pereopods I. Pereopods V are slightly longer than pereopods VI. The 

 2nd segment of pereopods V-VII is strongly broadened. Pereopods VI 

 have a full complement of segments. The rami of all the uropods are 

 lanceolate and the endopodite is not fused with the basipodite. 



Type species: Brachyscelus crusculum Bate, 1861. 



KEY TO SPECIES OF GENUS BRACHYSCELUS 



1. Head in males anteriorly narrowed. Lobe of antero-distal angle of 

 4th segment of pereopods I well developed. Telson longer than wide 

 at base 2. 



— Head in males anteriorly rounded, same as in females. Lobe of antero- 

 distal angle of 5th segment of pereopods I poorly developed. Telson 

 approximately equal in length to width at base 3. 



2. Basal segment of antennae II in males not shorter than following 

 segment. Distal segments of pereopods VII together shorter than 2nd 

 segment. Rami of uropods III (especially endopodite) strongly broad- 

 ened distally. Last urosomite equal in length and width 



1 . B. crusculum Bate. 



— Basal segment of antennae II in males much shorter than following 

 segment. Distal segments of pereopods VII together almost equal 

 to 2nd segment. Rami of uropods III almost not broadened distally. 

 Length of last urosomite 2/3 its width 3. B. rapax (Claus). 



3. Head equal to pereon in length. Anterior distal process of 2nd 

 segment of pereopods VI with straight lower margin, only slightly 

 extending beyond 3rd segment. Telson 2/3 length of last urosomite 

 and shorter than width at base 4. B. macrocephalus Steph. 



— Head not longer than first five somites of pereon. anterior distal pro- 

 cess of 2nd segment of pereopods VI smoothly rounded, reaching 

 middle of 4th segment. Telson longer than last urosomite, its length 

 equal to width at base2. B. globiceps (Claus). 



1. Brachyscelus crusculum Bate, 1861 (Fig. 213) 



Bate, 1861: 7; 1862: 333; Stebbing, 1888: 1544, 1547; Spandl, 1924: 

 32; Chevreux and Page, 1925: 427; Shoemaker, 1925: 45; Stephensen, 



