182 CHIONASPIS SALICIS. 



orange ; the dorsal spinnerets indicated by a double, 

 semi-elliptic series of dull crimson marks. Eyes black. 

 Rudimentary antennae normal. Eacli of the three 

 free abdominal segments with about nine large tubular 

 spinnerets at the margin, of the same character as 

 those of the pygidium ; and the last segment presents 

 a few stout, spiny plates. Pygidium (PL XXII, fig. 1) 

 with five large groups of circumgenital glands, which 

 vary considerably in numbers, as will be seen by the 

 following formula taken from seven examples on 

 willow : 



13 14 14 15 



3721 . 3028 . 3227 . 3332 

 2929 . 3124 . 2723 . 2721 



15 16 23 



3521 . 3840 . 3833 

 3030 . 3127 . 2633 



Dorsal tubular spinnerets, short and cylindrical, are 

 in twelve distinct series, forming three incomplete 

 arches. Within the first series, and immediately 

 behind the lateral circumgenital glands, are usually 

 three other tubular spinnerets. Anus and vaginal 

 opening opposite. The median and second pair of 

 lobes (PI. XXVII, fig. 2) are well developed ; the former 

 have the margins rounded, or faintly and roundly 

 serrate or dentate; the second pair are bilobed, the 

 anterior lobule very small, and both have the margins 

 rounded ; third pair are also divided or bilobed, the 

 posterior lobule usually dentate, the anterior lobule very 

 minute, and sometimes both are wanting. There is a 

 spine-like projecting pore between the median and 

 second lobes ; an angular one immediately posterior to 

 the third lobe, and there is a third midway between 

 the latter and the last group of plates. Two long 

 spines at the base of the anterior lobule of the second 

 pair of lobes, and another in a similar position at the 

 third lobes. Of the plates there is a short one between 

 the median and second lobes ; six others, long and 



