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 toxic 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 IV-j meters long. That death 

 was not due to a parasite introduced into the animal was shown 

 by examination of the blood. 



Mdhel Gunisey. 



ADDITIONS TO OUR KNOWLEDGE OF THE ANTS OF 

 THE GENUS MYRMECOCYSTUS WESMAEL 



WILLIAM MORTON WHEELER 



Psyche, Dec, 1912. 



All the known species and subspecies of the genus are within 

 the confines of the United States. 



M. meUigcr Diiiiiiciis Wheeler is described from several places 

 including Whittier, Cal. The variety semirufus from Point 

 Loma. M. nie.vica)ius mojave Wheeler was found in Pasadena 

 and Claremont. A photograph of a number of this species is 

 i'ei)i-odu('ed. 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 14 to ^ of an inch 

 across. They were in dry hard soil, along roads or paths in 

 situations where there was considerable vegetation, either 

 cliapai-ral, live-oaks or scrub-oaks. In such localities the ants 



