NORTH AMERICAN APTERYGOGENEA. 189 



size and tapering, they seem to be longer than the body. 

 The basal joint of the antennae is rather large and about 

 thrice as long as the following, nearly ball-shaped joint. 

 Of the annular small joints then following, the inner are 

 somewhat longer than the following, all of which are of 

 about the same length. The color of the antennae is 

 brownish black. The maxillary palpi are flame yellow, 

 and thickly beset with small black setae. The extremities 

 are also provided with short large setae, which, by their 

 dark brown, almost black color, make a sharp contrast 

 with the light ground color of the animal. This is 

 citrine, and on each tergit are running 8-10 orange 

 colored transverse lines. The joints between the several 

 segments are light yellow. The thoracic tergits are lighter 

 than the abdominal ones. The median cercus is not ex- 

 actly as long as the body. I cannot determine the length 

 of the lateral cerci, because they are hurt in all my speci- 

 mens. Probably they are much smaller than the median 

 one, for they are much thinner than this. 



Habitat. Sierra Nevada and Monterey, California. 

 (Coll. Miss Alice Eastwood.) 



Family LEPISMATID^ Burmeister. 

 Gen. Lepisma Linne. 

 Before entering on a detailed description of species, I 

 will point out a characteristic not before taken notice of, 

 which seems to me to be very useful for the distinction of 

 the species. It is met with on the cuticula, which is easily 

 laid bare by dissection or boiling in caustic alkali. The 

 cuticula then appears under the microscope either quite 

 smooth or ornated with a network of chitinous ribs. In 

 both cases it is lightly strewn with small, elevated anchor- 

 like figures, which are connected with the fastening of 

 the scales. 



