176 CALIFORNIA ACADEMY OF SCIENCES. 



but the head and the thoracic segments have to each other 

 a certain bend forward. The pronotum is quite concealed 

 by the mesonotum, which, however, does not project over 

 the posterior part of the head. The mesonotum is a little 

 longer than the metanotum, which also is somewhat longer 

 than the first abdominal segment. The second abdominal 

 segment is nearly thrice as long as the third; the fourth 

 occupies about half the body. The ocelli are sixteen in 

 number, eight on each side of the head. Their disposi- 

 tion will appear from the drawing. The antenna have 

 the basal joints strongly developed and reach almost to 

 the point of the mucrones, if the caudal appendage is 

 stretched out. They are four-jointed, and have the basal 

 and terminal joint of about the same length; the second 

 joint is nearly twice as long as the third. The outer joint 

 often fails. The tibial tenent hair is thick and enlarged 

 at the end, but not ball-shaped. The upper clazv is 

 slightly curved and provided with two teeth, extremely 

 small, which can be seen only under high magnifying 

 power. The furcula is very characteristic. The manu- 

 brium is not quite as long as the dentes, which slightly 

 taper towards the points. The mucronal segment being 

 of the same width and somewhat bent inwards, runs out 

 into three points. Before this segment there is hanging 

 down an elliptical scale, which is put into an excavation 

 in front at the point of the dentes. When examined by 

 the aid of an immersion -lens the scale seems dotted and 

 provided with a thick margin. Accordingly it has quite 

 another texture than the skin scales which characterize 

 several forms belonging to the family Entomobryidce. 

 The animal is thickly clothed with short hairs, above 

 which, at the joints of the segments in general, and espe- 

 cially between the first two thoracic segments, tufts of 

 club-shaped hairs are rising. These hairs, however, I 



