1917] Cockerell—Arthropods in Burmese Amber Al 
sixth subequal; third shorter. Bristles 
exceedingly abundant and long, dark 
fuscous. 
Burmese amber, from R. C. J. Swin- 
hoe; in the same piece as Electrofanus 
gracilipes, about 30 mm. from it. This 
appears to be a true Polyxenus, but it is 
remarkable for the very long and copious 
bristles. The species described by Koch 
and Berendt from Baltic amber have 
short bristles, and are entirely different. 
Our animal is curiously like an Anthre- 
nid larva, and on account of its long 
bristles resembles the much more an- 
cient Paleocampa from the Pennsylva- 
nian of Illinois. The structure figured 
at A, which I at first took for a pair of 
caudal appendages, is evidently the end 
Pane: 1. Polyxenus burmi- of a piece of vegetable débris which ap- 
pears on the other side. 
ACARINA. 
Cheyletus burmiticus sp. nov. (Cheyletidze). 
Length about 736 microns; shining reddish-brown, with very 
httle hair; mandibles ordinary; palpi extremely stout, strongly 
elbowed at base; claw well-formed, curved, on left palpus, but the 
right one appears minutely bidentate at end; thumb-papill 
lengthened, long and slender, ribbon-like, but not pectinate; legs 
as usual in the genus, so far as can be 
seen; abdomen broadly rounded poste- 
riorly. The following measurements are 
in microns: length of palpus about 208; 
second joint of anterior leg about 160, the 
third about 120; last joint of second leg 
about 160. . 
Burmese amber, from R. C. J. Swinhoe. 
In the same slab as the type of Winnert- _, Fig. 2. Cheyletus burmi- 
, te : ticus. A, palpi; B, base of 
ziola burmitica, and 3 mm. from it; also 6 first leg. 
