497 



402 1. Euthamneus rostratus (Bovallius, 1887) (Fig. 217) 



Bovallius, 1887a: 31 {Thamneus).—debilis Dana, 1852: 991 

 (Daira). — platyrrhynchus Stebbing, 1888: 1558 (Thamneus); Stephensen, 

 1925a: 180. — recurvirostris Chevreux, 1900: 154 {Thamneus). 

 Length of adult females up to 10 mm, of males up to 6 mm. 

 The body is flattened; the pereon is strongly broadened in the mid- 

 dle part, as if bulged, dolioform, and twice as long as the pleon. The 

 head in males is laterally sharply narrowed, terminating in a pointed ros- 

 trum, dorsally broad, truncate anteriorly, the width of the frontal margin 

 approximately half that at the base, and the width of the head much 

 more than its length. The head in females is also narrowed but anteriorly 

 evenly rounded and its height less than its length. The 1st segment of 

 the flagellum of antennae I in males is bent upward, thick, and relatively 

 short; the 2nd segment is highly flattened; the 3rd and 4th are narrower 

 and short. Antennae I of females are weaker and shorter than in males. 

 Antennae II are rudimentary in males, five-segmented, and not longer 

 than antennae I. 



Fig. 217. Euthamneus rostratus (Bovallius) (after Stebbing, 1! 



