XVII.—On two new species of humble-bees in the collection of the British Museum, constituting a new group of the genus Psithyrus, Lep. (Hymenoptera, Bombidæ)
- 1 January 1929
- journal article
- Published by Taylor & Francis in Annals and Magazine of Natural History
- Vol. 3 (13) , 139-143
- https://doi.org/10.1080/00222932908672947