136 . . , 



characters of the less common typical form and varying into it everyw- 

 here, and which Dr. Uhler first recognized under the name ndmitas. 



Many years ago I sent some typical s'pecimens of angustatus to Van 

 Duzee and they were determined by him as the Nydus thymi of Europe. 

 He also records //ij/mi for the vicinity of Buffalo, but does not mention 

 angusidtus though within the range of the latter as here understood. 

 I have had no authentic. European material of thymi and so cannot 

 work the matter out from the point of view of structure, However, 1 

 shall not be surprised to learn that angustatus is tJiyrid. 

 1403 Nysius senecionis Schill. 



On the West Coast of North America from Oregon through Nevada 

 and California to New Mexico, Mexico, and Lower California, there 

 occurs in abundance a medium sized, mostly pale testaceous Nysius 

 which presents remarkably distinctive characters of bucculae and other 

 parts. Dr. Uhler determined this for me as his strigosus and indepen- 

 dantly, Mr. Heidemann verified this determination. It is variable in 

 color though not nearly to the extent of angu&tatas. In coming to 

 compare it with the senecionis of Europe, I found myself unable to 

 separate the two on any constant appreciable characters. So we have 

 another case to add to the growing list of animals and plants common 

 to Europe and the west coast of America. Passing north into Oregon 

 individuals become more generally darker, as is true also in Mexico, but 

 these darker ones are also to be found among the lighter ones anywhere. 

 4410 Nysius coloradensis n. sp. 



This is somewhat similar to a small californicvs in size and general 

 appearance but differs widely from that species in structural charac- 

 ters. The bucculae are entirely different; the straight basal portion 

 of costal margin of corium extends about the length of the scutel before 

 it outcurves, whereas in californicus the basal straight portion is extre- 

 mely short, scarcely more than a fourth the length of the scutel. The 

 color is ashy or reddish-ashy with the general type of variable mar- 

 kings of califarnicus and some other species of Nysius and with a dense 

 silvery pubescence. The sides of the pronotum are unusually incurved; 

 the width across the eyes is to the anterior border is to the posterior 

 margin of pronotum as 9.5 is to 7.5 is to 11, the anterior margin of prono- 

 tum and length being about equal; membrane is nearly hyaline. In 

 the typical form the pubescence of pronotum is silvery white. Length 

 3.5 to 4.5 mm. I collected this species in large numbers in Colorado but 

 have not seen it elsewhere. 



Occurring among individuals of this species are larger ones with a 

 length often of 5 mm., very much darker, the membrane smoky and 

 dark spotted, the pronotum more coarsely and irregularly punctured, 

 and pubescence more scant and oehraceous. I have called this form 

 variety grayidis of the al)Ove species. 

 4373 Nysius ementitus Dist. 



Here is placed a considerable series of specimens collected in Nicara- 



