Specimens of the interesting new species described herewith came into the hands of both authors of this paper at about the same time from the same source, and were determined by each as new to science. Each being in ignorance of the fact that the other had received specimens, both proceeded to describe it. Before either description was published, however, the duplication was discovered through correspondence, and the description has been made the subject of this joint paper. The type and allotype specimens are in the United States National Museum, but paratypes are in the British Museum as stated below.