144 KANSAS UNIVERSITY SCIENCE BULLETIN. 



there is no constant character differentiating 7)ro^ews and ^)'?r- 

 gandei. 



SUMMARY. 



1. There have been no constant specific characteristics es- 

 tablished in the coccid genus Parlatoria on which to base a 

 system of classification. This is shown by the resulting con- 

 fusion and difference of opinion as to the status of many de- 

 scribed species. 



2. The shape and color of the scale and color of the body of 

 the female are so easily affected by change of environment, and 

 on observation of specimens are found to vary so much in the 

 same species, that it seems useless to look to these characters to 

 find constant specific characteristics on which to base a system 

 of classification. 



3. The pygidium of the female being less exposed to external 

 influences and being much used, it would seem that its char- 

 acteristic structures would be most likely to persist. It has, 

 therefore, been to this part of the body that the investigations of 

 this study have been directed. 



4. In the pygidium the dorsal glands have been found to 

 possess a certain constancy in character and arrangement, dif- 

 fering in the different species, but remaining quite constant in 

 the different individuals of the same species. 



5. A comparison of the results obtained by my investigations 

 with the opinions of the different authorities as extracted from 

 the available literature shows that in every case where the dis- 

 tinction of the form and arrangement of the dorsal glands was 

 found the status of the group as a valid species was unques- 

 tioned. On the other hand, where there was no distinction in 

 these glands the authorities were found to differ among them- 

 selves, and the characters given as distinguishing the species 

 have on investigation proved invalid. The classification made 

 on this basis was found on comparison to agree exactly with 

 Marlatt's synonymy, tentatively worked out and given in his 

 manuscript of 1900, except that pergandei, which Marlatt makes 

 a separate species, but says merges into proteus^ is here made 

 synonymous with 'proteus. On what basis Marlatt determined 

 his synonymy is unknown to the writer of this paper. 



6. Based upon the above-discussed characteristic of the form 



