Casey — A Revision of the American Paederini. 187 
species is a difficult matter and is rendered still less satisfac- 
tory because of the complete lack of variety in the male 
sexual characters; to such an extent is this true that the 
statement of these characters under each species would be of 
little or no value, for even in the otherwise isolated pollens, 
the only abdominal modification is the usual moderately deep, 
broadly rounded sinus at the apex of the sixth segment, which 
characterizes the entire genus. In my original description of 
tantilla, the prothorax is said to be ‘* scarcely perceptibly 
wider than the head,’’ but this is evidently a mistake, as the 
head is obviously very slightly wider than the prothorax,— a 
very exceptional character in the genus, although more frequent 
among the minute slender forms. For the present I have 
placed with the type of brevipennis, a specimen taken by my- 
self at Lake Tahoe, differing only in a few undecisive points, 
such as the rather less abbreviated elytra, and another 
specimen from Coeur d’Aléne, Idaho, which is somewhat 
more slender in form, less densely punctate and also with less 
abbreviated elytra. It is more than possible that each of 
these represents a species distinct from brevipennis, but the 
material at hand is insufficient to warrant a description of 
them, especially as all my representatives of this peculiar 
group, comprising brevipennis and quadripennis, are females. 
There is, however, little or no observable difference between 
the male and female in external form in those species repre- 
sented before me by both sexes. 
Pseudomedon Rey. 
In the European Catalogue of Heyden, Reitter and Weise, 
this genus is attached as a subgenus to Medon, with which it 
has no close affinity whatever. It is more evidently allied to 
Caloderma than to Medon, especially in the form and wide 
separation of the gular sutures, general facies of the body 
and small head, but differs from both in its edentate labrum, 
very minute and dense sculpture and strongly dilated anterior 
tarsi. The species are few in number but occur throughout 
the United States, as well as the palaearctic regions, the 
