418 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



and one side. The ventral scale is well developed, especially at the margin, where 

 it is much thickened and is dark colored; the central part is white and adheres 

 to the bark, while the thickened margin is easily removed as a ring. Diameter of 

 scale, 1.5""" (.06 inch). 



i^lewa/e.— The female is nearly circular, being but slightly longer than broad, and 

 is of a yellowish-brown color. The segmentation of the body is not very distinct. 

 The last segments present the following characters : 



Although forty-three specimens were carefully examined, no groups of spinnerets 

 were found. 



There are three pairs of well-developed lobes. The median lobes are rounded pos- 

 teriorly, or often with a slight notch on the lateral margin, and taper to a point 

 anteriorly ; the second lobe of each side is somewhat triangular in outline, with the 

 lateral edge serrate ; the third lobe is larger than either the first or second lobes, 

 triangular in outline and serrate on lateral margin. 



The posterior third of the lateral mai'gin of the segment appears to be of the same 

 structure as the lobes, and has five triangular serrate lobes; the posterior one of 

 these is the largest, and is larger than either of the true lobes. 



There are seven club-shaped thickenings of the body wall upon each side of the 

 meson, which are arranged as follows : One terminating near the lateral margin of 

 the first lobe ; this extends anteriorly but a short distance beyond the lobe. One 

 appearing to be a prolongation of the mesal margin of the second lobe; this extends 

 anteriorly to a point laterad with the anus. One terminating between the second 

 and third lobes; this is linear, inconspicuous, and sometimes obsolete. One termi- 

 nating at the base of the plates between the second and third lobes, and also one 

 terminating at the base of the plates between the third lobe and the thickened 

 lateral margin ; these two are the largest, and extend anteriorly the farthest of all 

 the thickenings, one terminating at the mesal margin of the third lobe, and one at 

 the mesal end of the thickened lateral margin of the segment. 



The plates between the median lobes and between the first and second lobes of 

 each side are verysmall and often obsolete ; there are two small irregularly branched 

 plates between the second spine and the third lobe, and also two similar plates 

 between the third spine and the mesal end of the thickened lateral margin. 



There are five pairs of spines on the ventral surface of the segment, and six on the 

 dorsal. Those at the base of the median lobes are very small, the others are con- 

 spicuous. The second and third spines of each surface are situated just laterad of the 

 second and third lobes respectively; in each case the dorsal spine is slightly mesad 

 of that on the ventral surface. The fourth spine of the ventral surface is on the 

 penultimate lobe of the thickened lateral margin. The fifth spine of this surface is 

 near the anterior end of the thickened part of that margin. The fourth and fifth 

 spines of the dorsal surface are in each case mesad of the corresponding spines of the 

 ventral surface. There is also a spine on the dorsal side, very near the penultimate 

 segment. 



Scale of male. — The scale of the male is oval in outline, and of the same color as 

 that of the female ; the protuberance covering the larval skin is near the anterior end. 

 The ventral scale is similar to that of the female, except that the margin is not so 

 much thickened. 



lfa?e.— Only dead and shriveled males have been observed. Described from forty- 

 three females and many scales of each sex. (Comstock Agr. Rpt., 1880.) 



59. Pseudococcus aceris (Geofi'rey). 



This species, stated by Signoret, according to Comstock, to be one of 

 the most common in France, would seem to be comparatively rare in the 

 United States. "It has been collected by Miss Emily Smith on maple 

 {Acer saccliarimim) at Peoria, III., and forms the subject of quite an ex- 



