1935 ] 
Mimetic Flies 
101 
Tenthredomyia. I do not believe that a subgeneric assign- 
ment should be made upon it, lacking a male specimen, and 
also in view of the fact that there is a slight antennifer, it 
seems best to consider it as a highly aberrant Cerioides. 
Tenthredomyia ancoralis Coq. 
One male. Las Cruces, New Mexico. July (F. M. Hull) 
on flowers of privet. 
Tenthredomyia abbreviata Loew. 
Several specimens, males and females, near Ames, la., 
July 19 (F. M. Hull). 
Tenthredomyia tridens Loew. 
A large series collected by A. Spuler at Toppenish, Wash., 
July 22 to August 1. 
Tenthredomyia mime n. sp. (Plate 9, fig. 1) 
An odd species, of bluish black coloration with ivory white 
markings. The color, together with the entirely dark wings, 
with their blue and purple irridescence, makes it a very 
unique member of the North American Cerioidini. It bears a 
striking resemblance to a bluish-black species of wasp. 
Length 15 mm. including antennae. Female. Vertex ivory 
white, the upper occiput on either side and the front and re- 
gion about occelli black, the latter with a V-shaped intrusion 
posteriorly into the white of the vertex. Antennifer, its base, 
and a short space below broadly extending to the eyes and 
continued medially as a narrow facial stripe, black. The face 
with a large, white triangle on either side and a small, white 
spot on the margin of the eyes just opposite the antennifer 
together with a pair of similar smaller spots just above the 
base of the antennifer. The median black stripe of the face is 
connected with the black oral margin and the cheeks are 
broadly and entirely black. Antennae entirely black. The an- 
tennifer equal in length to the first and second joints and 
these latter segments of equal length. The third segment 
slightly longer than the second. The style quite short. 
The thorax entirely black save for a white spot on the hu- 
meri, and mesopleurse, and a smaller one before the base of 
