110 



REPORT UPON A COLLECTION OF 



Pygidium (Fig. 31) with three pairs of lobes, the median pair alone 

 well developed, these simple and rounded at the tip, the second and 

 third pairs very small, simple and scarcely projecting beyond the margin. 



Fig. 31 Chionaspis distichlii n. sp. : pygidium of adult. 



Near the base of each lobe is a pair of quite large gland spines and be- 

 tween the third pair and the anterior margin of the pygidium is a single 

 gland spine. The marginal and submarginal ducts are quite large, those 

 of the dorsum for the most part smaller, all very few, their arrangement 

 as indicated in the figure. Anal opening quite large, somewhat in ad- 

 vance of the center of the pygidium. Microducts all very minute. 

 Ventral side with three rows of very small tubular ducts and with three 

 or four pairs of quite large spines at some distance from the margin. 

 Circumgenital pores in three groups of 10-15 pores. 



Second stage closely resembling the adult except for the absence 

 of all but the marginal ducts. 



First stage with the antennae 6-segmented, all the segments very 

 short except the first and sixth which are slightly elongate, the latter 

 not annulate. Pygidium without lobes but with two or three pairs of 

 gland spines. 



Notes: This species is a member of a rather characteristic grass-infesting 

 group to which belong such forms as C< spartinae. From this, the only American 

 member of the group, it differs in the inconspicuous lobes and the small number 

 of dorsal ducts. 



