264 



THE CANADIAN ENTOMOLOGIST. 



On the subsequent plates the entire carinal margin presents about 

 twelve distinct teeth. In preceding caudad the caudo-lateral angles of the 

 carinas become first more and more rectangular, and then more and more 

 distinctly produced caudad as usual. 



Anal scutum with conical setigerous tubercles well developed ; 

 arranged in transverse rows. Each lateral margin with about seven dis- 

 tinct serrations. Apical process rounded distally ; not decurved. 



Anal valves smooth ; mesal edges strongly margined. Lateral mar- 

 gins widely convex. 



Anal scale with the lateral margins incurved. Caudal margin deeply, 

 concavely excised, leaving at each lateral angle an acute conical projection. 



Sterna with both longitudinal and transverse sulci distinct, the longi- 

 tudinal one more sharply impressed. 



Legs of median length ; hirsute. In the male the second pair of legs 

 of the ninth segment have a conspicuous, flattened appendage extending 

 dorso-caudad from the distal end of the penult joint. Similar processes are 

 present on both pairs of legs of the succeeding three segments, but the 



processes become progressively 



Fig 16. — Scylonoius Bergrothi, sp. nov. — Gonopods 

 of the male seen in caudo-vtntral aspect. 



10 



smaller on the legs of the thir- 

 teenth segment, being obscure 

 or absent as such. 



The gonopods of the male of 

 the general form typical for the 

 genus, but differing in details 

 from those of the previously de- 

 scribed species. (See fig. i6,) 



Length, 1 7 mm.; width, 

 2.3-2.4 mm. 



Locality. — Bremerton, Wash. 



Five specimens collected by 

 Dr. Bergroth, after whom the 

 species is named. 



Polydesmus bonikus Chamberlin. 

 1911. — Po/ydesmtts bonikus, Proc. Acad. Sci. Phil. 

 One specimen from Madison, Wash. 



II. Leptodesmus artnatus (Harger). 



1872 — Polydesmus armatus^ Amer. Jour. Sci., 3rd ser., Vol. IV, 

 p. 118. 



A number of specimens from Madison, Wash. 



