44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



verse row. The last sternite is infolded on the apex. There occur no 

 striking differences in either different species or in the two sexes. 



Spiculum ventrale.- — ^In the females of all three species the spiculum 

 ventrale is well developed. By careful dissection it can be seen 

 fastened to the Fortsatzlappen Verhoeff. Without any doubt we 

 are dealing here with a true spiculum laterale clausum (Fuchs). The 

 median line commissura, which gives by certain modifications the 

 spiculum ventrale opportum, is especially well defined in Gn. maferi- 



St ^— /— 



Fig. 23, A. — Gnathotrichus rctusus Lee. : Sixth and seventh sternites of a female 

 with the spiculum ventrale. 



Ca, caput; CoJ, conjunctus lateralis; Com, commissura; Br, brachium; Ra, radix; st, sternites. 



St a 



St. 



Fig. 23, B. — Gnathotrichus rctusus Lee. : Seventh and eighth sternites of a male. 



arms Fitch and retusus Lee. For further studies on this subject it is 

 proposed to name the different parts of the spiculum. The part 

 where the spiculum joins the seitlichen Ansatzlappen (Verhoeff), 

 seitlichen Lappen (Fuchs), may be called radix spiculorum ; the more 

 or less chitinized, sometimes membranous bands extending anteriorly, 

 brachium ; and the apically thickened part, caput. The seitlichen Lap- 

 pen (Fuchs), Fortsatzlappen (Verhoeff) should be called the con- 

 junctus lateralis. The spiculum ventralis of Gn. snkatus Lee. may be 

 easily distinguished from the others by its slimmer brachiae. Gn. 

 retusus Lee. and Gii. niateriarius Fitch show no striking differences 

 in this regard. 



I 



