Packard,] 178 [June 16, 
Synopsis of the Genera. 
A. Body not setose ; antennse long ; male legs of eighth pair not modified; 
genital armature of normal proportions. ...,.Lysiopetalum Brandt. 
Male legs of eighth pair modified, six jointed ; genital armature small 
Pscudotremia Cope. 
B. Body setose. 
Body short and thick, eyes triangular; antenne slender; sets one- 
fifth as long as body is thick ; legs short..... Oryptotrichus Packard. 
Body short and fusiform, eighth pair of legs of male two-jointed ; setw 
half as long as body is thick..........-. ..+. Lrichopetatum Harger. 
Body slender ; eighth pair of male legs two-jointed, ending in a claw ; 
sete very long ; CYel€SS.....+sseeroreeererssersens Scoterpes Cope. 
Like Scoterpes ; sete a little shorter; sixth pair of male legs greatly 
POOH is tiv ade eoleec dhledeiuniln Vue veeeygonopus Ny Cer, 
Characters of the Family. The diagnostic characters of the group, as 
distinguished from the Julide, are as follows ; Head broad, wider than the 
body in front; gene much swollen, front flat ; eyes situated in a triangle, 
often partly or wholly aborted; antenn®w seven-jointed, much longer 
and more setose than in the Julidw, especially the third and fifth joints, 
and also the seventh (terminal) joint. Body subfusiform, constricted be- 
hind the head, the first and second segments being much narrower than 
in the Julide. The segments usually divided into an anterior raised por- 
tion, often with longitudinal ridges, and a posterior plain depressed 
smaller portion ; on the sides of the anterior portion of the segments of 
the anterior half or two-thirds of the body a swollen boss or hump, with 
three setiferous tubercles ; the sete: from one-third to two-thirds as long 
as the body is thick. Feet very long and slender, as long as the body is 
thick, or sometimes longer. The coxe contiguous, the sterna very rudi- 
mentary, not united with the scuta. In the males the sixth pair of feet 
enlarged and swollen (in Zygonopus) ; the eighth pair two-jointed and 
rudimentary ; number of body-segments variable ; end of body pointed. 
To enter into more detail, the following comparative description of the 
family characters may be useful : 
The Head. The head of the Lysiopetalidee is more like that of the Poly- 
desmide than the Julide ; the gene are remarkably swollen, and as in 
the Polydesmid separated by suture from the rest of the epicranium ; they 
are higher and narrower oval than in the Polydesmidx. The front of the 
head is much flattened, forming a squarish pseudo-clypeal region sepa- 
rated by a faint suture from the epicranium ; the sides of the head or genal 
region are swollen, forming a slight median depression on the vertex, 
The labrum is much asin the Julide, with three median nearly’ equal 
teeth, and with four sete on each side asin the Julide. Finally, in the 
form and anatomy of the head, the Lysiopetalide approach the Polydes- 
mide more closely than the Julide ; the nearest approach to the family in 
