HENRY J. FRANKLIN. 455 



Nebraska. It is probably present in Iowa, South Dakota, 

 North Dakota, Kansas, Missouri, northern Georgia and 

 northwestern South Carolina, and it is possible that exten- 

 sive collecting will extend its habitat even beyond these 

 limits. It seems to be rather strictly confined to the Transi- 

 tion and Upper Austral Zones, being apparently most abun- 

 dant in the eastern part of its range (Swenk reports the 

 capture of only two specimens in Nebraska). 



The females of this species are most closely allied to in- 

 sularis and the males to consiiltus, as shown by their structure 

 in each case. 



I follow Walsh, Robertson and Lovell in considering citri- 

 nus F. Sm. and contiguus Cress, to be males of laboriosus F. 



I do not know of their having been taken in coitu or in the 

 nests of Bombus. The evidences of their relationship are as 

 follows : 



1. Similarity of appearance. — These males resemble the females of 

 laboriosus in coloration more closely than do any other male Psithyri 

 of the New World, known to me. 



2. Concordance of habitat . — These males have the same geographical 

 range as the females of laboriosus , and are taken in corresponding 

 abundance in the different parts of that range. No other males known 

 to me come anywhere near fulfilling this requirement. 



In my opinion, Fabricius' description of Apis data fits the 

 citrinus variation of the male of laboriosus better than any 

 other form of either Bombus or Psithyrus in North America 

 known to science. 



Psithyrus insularis (F. Sm.). 



II Bombus interruptus Greene, Ann. Lye. Nat. Hist. New York, VII, 



1858, p. 11, n. 1, 9 . 

 " " Greene, Ann. Lye. Nat. Hist. New York, VII, 



1860, p. 173, n. 11, 9 . 

 Apathus insularis Smith, Journ. of Ent., I, 1861, p. 155, n. 2, 9 . 



Cresson, Proc. Ent. Soc. Phila., II, 1863, p. 113, n. 

 6, 9 (not the cf). 

 " " Cresson, Proc. Davenp. Acad. Nat. Sci., I, 1876, p. 



210. 

 '* " Cresson, Trans. Amer. Ent. Soc, VII, 1879, p. 230 



(Catal.). 



TRANS. AM. KNT. SOC, XXXVIII. 



