644 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



Genus VANBENEDENIA Malm. 



Generic characters of female. — Cephalothorax and trunk in the same 

 straight line but separated by a well defined groove; the former short 

 and much broader than long, without a dorsal carapace, the latter 

 elongate, depressed, and indistinctly segmented; no posterior proc- 

 esses, genital process, abdomen, or anal laminae; first antennae short 

 and unsegmented; second antennae uniramose; first maxillae bi- 

 partite, without palps; second maxillae straight and rigid, approxi- 

 mated for their entire length and fused at their tips, where they are 

 joined to a mushroom bulla; egg strings filiform and much longer 

 than the trunk. 



Generic cliaracters of male. — Cephalothorax and trunk in the same 

 line and thoroughly fused, the separation being indicated, if at all, 

 by a slight groove; no dorsal carapace; trunk shorter than the 

 cephalothorax, conical, and bluntly rounded posteriorly, without any 

 abdomen or anal laminae; antennae and mouth parts like those of 

 the female; second maxillae and maxillipeds some distance behind 

 the mouth tube (see pi. 28, fig. N). 



Type. — Vanhenedenia hr^yeri, the single species. 



{Vanhenedenia, to P. J. van Beneden.) 



'PR^CHEJIjIASTIlSrAE!, new stabfamily. 



Subfamily cliaracters of female. — Cephalothorax shorter than the 

 second maxillae, much narrowed and flattened, in line with the trunk 

 or bent a little backward; trunk elongate, flattened dorso-ventrally, 

 enlarged posteriorly, with no traces of segmentation, no posterior 

 processes, genital process, abdomen, or anal laminae; maxillipeds 

 on the inner surface of the second maxillae, and the two removed a 

 long distance behind the mouth tube; second maxillae united only 

 at the tip, bulla mushroom shaped. 



Male. — Unknown. 



Remarlcs. — Since this subfamily includes but a single genus its 

 characteristics for the present will be the same as those of the genus. 

 The most marked character is the juxtaposition of the second max- 

 illae and maxillipeds and their removal a long distance behind the 

 mouth tube. 



Genus TRACHELIASTES Nordmann. 



Generic cliaracters of female. — Cephalothorax separated from the 

 trunk by a well-defined groove, and usually strongly curved; no 

 dorsal carapace; first antennae indistinctly jointed; second antennae 

 biramose, each ramus unsegmented and ending in a claw; first max- 

 illae tripartite, without a palp; second maxillae long, stout, and 

 wi'inkled, united only at the tip to a mushroom-shaped bulla; max- 

 illipeds small, with weak claws; egg strings large and about as long 

 as the trunk. 



