488 



XX. Family BRACHYSCELIDAE Stephensen, 1923 



Crustaceans of 5-20 mm in length. The body is oblong and laterally com- 

 pressed. The eyes are large and occupy almost the entire surface of the 

 head. The flagellum of antennae II in males has a short apical segment or 

 it is rudimentary. The mandibles in males have a palp, which is absent 

 in females. Maxillae I and II are markedly reduced. The subchelae of 

 pereopods I and II are well developed, broad, with coarsely denticulate 

 margins; moreover, the largest denticles often also have denticulate mar- 

 gins. Pereopods V and VI differ less in length; the 2nd segment is broad 

 but not operculiform. Pereopods VII consist of a broadened 2nd segment 

 and generally 3rd-7th distal segments. The rami of all the uropods are 

 free and have denticulate margins and a pointed tip. The telson is not 

 fused with the last urosomite. 



Claus (1879b; 1887) placed the genus Brachyscelus (Thamyris) in 

 the family Lycaeidae along with the genera Lycaea, Simorhynchotus, 

 Paralycaea, and Pseudolycaea; Stebbing (1888) included the genera 

 Euthamneus and Brachyscelus in the family Tryphanidae together with 

 the genera Tryphana, Lycaea, Paralycaea, and Simorhynchotus. In struc- 

 ture of pereopods I, II, V and VI, Brachyscelus and Euthamneus occupy 

 an intermediate place between the families Lycaeidae and Oxycephali- 

 dae. Hence their inclusion in an independent family (Stephensen, 1923) 

 seems justified to us. 



The family includes two genera. 



KEY TO GENERA OF FAMILY BRACHYSCELIDAE 



1 . Head of male flattened and anteriorly extended into short pointed ros- 

 trum. Antennae II in males rudimentary, not longer than antennae I. 

 Pereon dolioform. Second segment of pereopods VI approximately 



half length of remaining segments together 



2. Euthamneus (Bov.). 



— Head of male may be narrowed anteriorly but not forming pointed 

 rostrum. Antennae II in males long, folded four times, longer than 

 antennae I. Pereon not dolioform. If 2nd segment of pereopods VI 



shorter than remaining segments together, very slightly so 



1 . Brachyscelus Bate. 



1. Genus Brachyscelus Bate, 1861 



Bate, 1861: 7; Stebbing, 1888: 1543; Stephensen, 1923: 37; Chevreux 

 and Page, 1925: 426.— Thamyris Claus, 1879b: 32; 1887: 56. 



The head is large, in females anteriorly smoothly rounded and higher, 

 in males anteriorly more or less narrowed, its height generally not more 



