NORTH AMERICAN CADDIS-FLY LARVZ. 
a few minute setz ; segment eight is bordered along its hind dorsal 
region by a dark area which bears a row of about six sete; seg- 
ment nine curves sharply downward and is darker in color than 
segments two to eight; it bears a dorsal chitinous plate which is 
LIMNOPHILUS COMBINATUS. 
51. Larva. Head and thorax. 56. Case. 
52. Case. 57. Larva. Distribution of gills. 
53. Larva. Labrum. 58. Pupa. Chitinous plates of left 
54. Larva. Lower mouthparts. side of abdomen. 
55. Larva. Frons. 
armed with four large and several smaller sete; there are also 
several strong setz in the region of the drag-hooks; on the under 
side of each segment, two to seven, there is a narrow hair-like 
mark, oval in shape; the lateral fringe is short and black. The 
distribution and number of gills on the left side of the body 
are indicated diagrammatically in figure 57. 
DESCRIPTION OF THE Pupa.—tlLength, 20—22 mm.; breadth, 
about 5 mm. The antenne extend back to about the hind margin 
of the seventh segment; on the dorsal surface of the head, between 
the antennz, there is a pair of strong sete, and on the front sur- 
face, midway between the dorsal sete and the labrum, there is a 
pair of similar sete ; each lobe of the labrum bears a group of stout 
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