46 Psyche [April 



pages it will appear that nothing but a closer study is needed 

 (especially with the new binocular dissecting microscopes) to 

 find characters almost if not quite as interesting as those of Doli- 

 chopus. 



The North American species were so little known at the time 

 of Loew's monograph of the family that he could describe only 

 three species, to which he afterward added two in the later part 

 of his Centuries. The principal contribution to the genus since 

 that time has been by Wheeler (Proc. California Acad. Sciences, 

 3rd ser. Zool. Vol. II, pp. 62-69, 1899) in which a table of 

 species is given, five new species described, and numerous excel- 

 lent figures published, showing especially the spinulation of the 

 front femur and tibia, which had been but little appreciated before. 



Walker described four species in this genus, of which I think 

 I recognize chrysologus, which had before been identified with 

 his name glaber; the rest are mentioned at the end of this paper. 

 Say's Medeterus lateralis I consider to be a Neurigona, and his 

 punctipennis to be a Pelastoneurus. 



Bibliographic references are given herein only where they correct 

 or add to those of my Catalogue, now generally accessible. 



A few suggestions about specific characters in the genus will 

 doubtless be of use to those who undertake to determine specimens. 



A highly interesting and heretofore unreported character is 

 the presence in three of our species of a row of bristles across 

 the occiput (fig. 4); as the usual pair of postvertical bristles 

 are included in the row, I have referred to them all by that term. 

 The black bristles which form a row beliind the upper part of 

 the eye I have termed the postorbitals; they extend much farther 

 down in some species than in others. Beneath the neck among 

 the pale hairs called the beard are sometimes several black bristles; 

 they are too hard to see to be of much importance in classification, 

 but I have mentioned their occurrence when I could see them. 

 The width of the cheek at the lower edge of the eye is an impor- 

 tant character, but it is difficult to measure it by anything very 

 tangible; the student will need to gain his ideas by com])aring 

 several species. The metallic color of the face, and its alterna- 

 tive, the complete opacity of the face, might not seem to sound 

 very definite, but I think they work out very well. I find hardly 

 a species difficult to place by this character. The antennae 



