NORTH AMERICAN APTERYGOGENEA. I 79 



joints of about the same length and the terminal joint nearly 

 twice as long as the preceding. The upper clazv has three 

 teeth, the two interior of which are very large. At the 

 first glance we can distinguish only two teeth, owing to 

 the circumstance that the two interior are placed beside 

 each other. By the aid of a strong microscope and with 

 different focusing of the tube, it can, however, easily 

 be observed that the bases of the two teeth are parallel 

 and situated on each side of the claw, and that their 

 respective points diverge, so that they are angular to each 

 other. On a preparation, the lower tooth, with a precise 

 regulation of the tube, seems to be very strongly devel- 

 oped, while the upper one seems to be much smaller. 

 The difference is owing to the inferior tooth appearing 

 in its whole extent from the side, while the upper one 

 appears only in part and from above. The lower claw is 

 lanceolate and without any teeth. There is a tibial tenent 

 hair, but with no swelling at the point. As to the form 

 of the caudal appendage, there is a complete coincidence 

 with the preceding species. 



As the scales are more or less completely fallen off, the 

 color of alcoholic specimens is pure white. 



Habitat. Berkeley, California. (Coll. G. Eisen.) 



Entomobrya curviseta Brook. 



Dirty white, marked zvith brown spots. The eyes are 

 four, two on each side of the head. The terminal joint of 

 the antenna is longer than the third. The upper clazv has 

 three teeth, the two interior of which are very strong and 

 placed beside each other. The lower claw is lanceolate 

 and unarmed. The mucro is provided with two hooks. 

 Length 2 mm. 



Syn. 1882, Sinella curviseta Brook, Linn. Soc. Journ. 

 Zool., vol. xvi, p. 541. 



