Mar., 1903.] Food Plants of Some Bythoseopidae. 399 



P. viridis Fitch. — This species appears to be strictly confined to 

 the narrow-leaved willow ( .S". lojigifo/ia). The adults appear the 

 middle of June. 



GENUS IDIOCERUS. 



The American forms of this group have been recorded from 

 only three genera of plants and these all tree forms. The follow- 

 ing notes add as many more genera to the list and introduces for 

 the first time strictly bush forms as host plants. Wherever wil- 

 low forms have been studied they have been found confined to one 

 species or to a group of closely related species of willows and not 

 general feeders as has been commonly supposed. 



/. dolosiis Ball. — Found only on the bushy Sumac (R/iits aro- 

 ma fica) in the mountain region of Colorado. Adults have been 

 taken from the middle of July until late in August. 



/. raiii€)itos2(s Uhl. — Common on Sa/ix kvigifolia, seeming to 

 prefer the short, thick clumps and sheltered locations. Found in 

 Iowa, Nebraska and Colorado. 



/. snoci'i G. and B. — found on S. longi folia. 



I. lachryiualis Fitch. — found only on the Quaking Asp {Popu- 

 /iis troiiuloidcs). 



I. fcmoraUis Ball. — is a willow form, but has not been found in 

 sufficient numbers to determine which species of willow it lives on. 



/. prodiidus G. and B. — is also a willow form. 



/. Diorosus Ball. — This was swept commonly from two species 

 of Ribes growing in the foot hills and mountains west of Fort 

 Collins, Colo. It was most frequently met with on the red cur- 

 rant or squaw berry {R. crrcuiii. ) 



I. verrucosus Ball. — w^as also taken on currants at about the 

 highest altitude at which they grow. 



/. ensiger Ball. — This is probably another currant form, though 

 not enough specimens were taken at any one time to eliminate the 

 possibility of it being an accidental capture. There were two 

 very distinct kinds of larvae found together on the squaw berry — 

 one, dark reddish brown that apparently belonged to this species, 

 and a green form that was probably )iiorosus. 



I. aiiiocDius Van D. — This pretty species lives on the Juniper, 

 where its rufous and green match well with its surroundings. 



/. jicrvatus Van D. — This species has been reported as occur- 

 ring on willows, but in Colorado it seems to be an inhabitant of 

 the Juniper. It is possible that there are still two species mixed 

 under that name. 



The American Association. ' 



We have been interested in noticing the membership of the 

 American Association for the Advancement of Science from the 

 different Universities of the country, as shown by a Geographical 

 list recently published b}' the Association. 



