62 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 
siderable variation in color due to a difference in nourishment. 
Those which suck blood are a blue-gray color, while those which, 
due to unfavorable location or overcrowding are forced to live 
upon lymph, are of a much lighter color. A complete descrip- 
tion of the life history, which covers at least ninety days, is 
given, as two generations were reared in the laboratory and 
careful observations made. An interesting result of these 
observations was the discovery that there were no males among 
the several thousand specimens examined. The experiments 
are now being continued, with the purpose of studying this 
parthenogenesis, and the results will be published later. 
Animals bitten by these ticks apparently suffer not only from 
loss of blood, but from a toxie substance secreted by the tick, 
as the bite of more than ten proves fatal to a toad or of about 
one hundred to a boa constrictor 114 meters long. That death 
was not due to a parasite introduced into the animal was shown 
by examination of the blood. 
Mabel Gurnsey. 
ADDITIONS TO OUR KNOWLEDGE OF THE ANTS OF 
THE GENUS MYRMECOCYSTUS WESMAEL 
WILLIAM MORTON WHEELER 
Psyche, Dee., 1912. 
All the known species and subspecies of the genus are within 
the confines of the United States. 
M. melliger mimicus Wheeler is described from several places 
including Whittier, Cal. The variety semirufus from Point 
Loma. M. mexicanus mojave Wheeler was found in Pasadena 
and Claremont. A photograph of a number of this species is 
reproduced. In Claremont the nests of about twenty were 
examined. ‘‘The craters of these were found to vary from 4-8 
inches in diameter, with a central opening 4 to 34 of an inch 
across. They were in dry hard soil, along roads or paths in 
situations where there was considerable vegetation, either 
chaparral, live-oaks or serub-oaks. In such localities the ants 
