OF WASHINGTON. 121 
There is, however, a third joint situated at the apex of joint 
ii, which is so reduced in size as to be easily overlooked, 
being only about one-third the length of the scales with which 
the second joint is clothed. 
Labrum small, trapezoidal, widest in front and supporting 
four regularly placed spines on the front edge. Mandibles 
simple, sickle-shaped, sharp-pointed, grooved on upper sur- 
face. Maxillary palpi four- jointed, second joint very large, 
terminal joint very small, cylindrical. 1 Maxillae very small, 
almost hair-like, about one-fourth as long as palpi, very incon- 
spicuous. Labium small, trapezoidal, bearing two- jointed 
palpi which project almost as far as the maxillary palpi. 
There is nothing extraordinary about the legs, which each 
bear a single large simple claw, the latter apparently not 
being articulated with the tibia. 
In addition to the median row of dorsal tubercles there are 
three main lateral rows of chitinized spots on the abdominal 
segments, which become confused and irregular on the thoracic 
segments. I am unable to see spiracles on the thoracic segments 
or the last two segments of the abdomen, but there is a very 
distinct spiracle near the outer edge of each of the first seven 
dorsal abdominal segments just in front of the outer chitinized 
spot. 
The last abdominal segment is produced into a conical tail 
which bears on each side at base three lateral spines each 
surmounted by a triangular scale (Fig. 12, A). The upper sur- 
face of the tail shows a row of about nine tubercles. 
Perhaps the most conspicuous characteristic is the lateral 
fringe which is about one-sixth, of the entire width and is 
composed of fourteen lobes on each side, two on each thoracic 
segment and one on each abdominal segment except the last. 
Each lobe consists of a curved central stalk from either side 
of which arise four to twelve curved processes, the tip of each 
being truncate and bearing a fluted, triangular scale. These 
processes are homologous with the tubercles and modified 
hairs, described above, which cover the whole body. 
It is hoped that future observations will solve the mystery 
connected with this interesting larva. 
Mr. Knab presented the following communication: 
'In one of the specimens there is a queer deformity, the second joint 
giving rise to an extra third and fourth joint on the upper surface. 
