1883. ] 191 [Packard, 
This Myriopod is a rather characteristic form, and appears to range from 
Pennsylvania to the Gulf States. 
TricnorperaLuM Larger. 
Trichopetalum Harger, Amer. Jour. Sc. Arts, iv, 118, 119, Aug., 1872. 
Body rather short and thick, fusiform compared with the succeeding 
genera, being thicker in the middle and tapering more towards each ex- 
tremity than in Scoterpes and Zygonopus. Head of the general shape 
of that of Zygonopus, the proportions of the front and vertex being about 
the same; but the gena is much fuller, more globose, and the genal are: 
is shorter and rounder. The eyes are present, black, the facets 10-19 in 
number, arranged in two curvilinear series, the eye-patch being lunate in 
shape. The antenne are short and thick, much more so than in Scoterpes, 
pilose, with a few rather coarser sete than usual ; joint 2 is but slightly 
more than half as long as joint 8, and rather shorter than joint 4; joint 3 
is conside rably longer than joint 5, the latter being thick, subpyriform 
and swollen toward the end; joint 6 is much swollen and rounded, and 
about as thick as long ; the seventh or terminal joint is shorter than in any 
other genus of the family, being rather shorter than in Scoterpes ; and 
with two flattened sensory terminal sete. Number of body segments, 28- 
31; number of pairs of legs in the female, 46. The legs are much shorter 
than in Zygonopus. The scute are posteriorly a little swollen on the 
sides, much less so than in the two following cave-genera ; the bosses 
being not much over half as large ; from the upper part of the boss or 
shoulder arise three warts or tubercles arranged as usual in a scalene tri- 
angle, and giving rise to short, rather stiff sete, which are half as long as 
the segment is thick. 
In the male the three pairs of legs in front of the genital armature are 
slightly longer than those behind or in front, but the seventh pair or that 
directly in front of the rudimentary eighth pair are not swollen, nor do 
they in any way resemble the swollen pair in Zygonopus. The eighth or 
rudimentary pair are two-jointed, the outer joint without a claw, only 
sending off a few small sete. 
The genital armature is somewhat similar to that of Zygonopus, but 
better developed. I could detect no lateral pores. 
Mr. Harger gave the following diagnosis of the genus: ‘‘Sterna not 
closely united with scuta; third and fifth joints of antenne elongated ; 
scuta furnished with bristles; no lateral pores; eyes present.’’ He does 
not attempt to give any generic characters drawn from the genitals, and 
in his description of 7. lunatum, says: ‘‘The under side of the seventh 
segment of the male (Fig. 8) is furnished anteriorly with a pair of appen- 
dages directed backwards and curved upward,’’ and then describes the 
rudimentary eighth pair of legs. Our description of the genus has been 
drawn up from Mr. Harger’s types belonging to the Museum of Yale Col- 
lege, kindly loaned us for study. On such examination as we could make 
without dissection, the genital armature is evidently more perfectly devel- 
