362 Annals Entomological Society of America [Vol. VIII, 
southernmost point from which we obtained specimens of the 
so-called European ox warble. However, but a single grub was 
collected in this locality, and on account of the fact that this is 
a concentration center of considerable importance it may be 
that the infestation was recently introduced on cattle shipped 
from elsewhere and will not persist. The specimen taken was 
found on a dairy cow in a herd on the edge of the city. A well 
established center of infestation occurs almost as far south as 
ir 
D 
a 
oar 
Fig. 1. Map showing the distribution of the ox warbles in the United States. 
The dots indicate where Hypoderma lineata has been collected in this investigation; 
the crosses indicate Hypoderma bovts. 
St. Louis, at a point in western Maryland. This locality is in 
the Allegheny Mountains, and the infestation appears to extend 
continuously northward through Pennsylvania into New York. 
The correspondent who collected these specimens states that he 
does not know that any cattle have been brought into that 
locality from the north for a great many years. It was thought 
that possibly H. bovis might be best adapted to the conditions 
in the northern part of the country, especially along the 
mountain ranges. While this theory seemed to be fairly true 
for the eastern part of the country, it was not borne out by 
