No.]3,s2. THE ACARINA OR MITES— BANKS. 45 



The internal iinatoniy of the Ixodidji? ha.s been examined hy Ileller 

 (1848) and later by Pagensteeher (18(31). The pharynx ,soon contracts 

 into a slender cesophagu8, which, as usual, passes through the "brain" 

 and into the stomach. The latter is not very large, but has several 

 diverticula or cieca, some in front, and usually four large ones behind 

 and one longer on each side. The color of the food in the can-a often 

 shows through the integument, so that the same species at ditterent 

 tinies exhil)its different markings on the body. 

 Upon this basis the earlier authors often de- 

 scribed one species under several names. The 

 intestine is short and straight, enlarging some- 

 what before the anus. The breathing apertures 

 or spiracles open into a large sac, which soon 

 divides into a host of small trachet^^ that spread 

 out in the l)odv cavitv. In the anterior part ^''^- 76.-stigmal plate of 



, * * • 1 1 1- BOOPHILUS ANNUI.ATI'S. 



of the body are two large, botryoidal salivary 



glands, opening through a duct x'ach side of the mouth. The female 

 genital organs consist of two elongate ovaries, each with a slender ovi- 

 duct, which unite shortly before the vulva. The male organs consist 

 of the two slender testes, each emptying into a large median sac, from 

 which a slender duct leads to the opening. 

 The Ixodoidea are readily divided into two families. 



No scutum; no ventral shield; niouth-parts of a<lult not prominent from aliovt-; no 

 pulvillus to tarsus in adults; stignial plate between coxse III and 1\ ..Avgosldir 



Scutum present; sometimes ventral shields; mouth-}iarts of adult prominent from 

 above; pulvillus to tarsus of both adults and young; stigmal plate behind 

 coxie IV I.rodiihf 



The Argasidae, containing but few genera, are in some ways inter- 

 mediate between the true ticks (Ixodidcu) and the Dermanyssida^. 

 The skin is- usually covered Avith granulations or deeply pitted and 

 the head and mouth-parts are hidden beneath the anterior part of the 

 body. They are nocturnal in habit and feed on the blood of mammals 

 (including man) and ])irds. Unlike the true ticks, the females of this 

 family do not l)ecome so greatly distended with blood. There are 

 two genera in our fauna. 



Capitulum at least its length from the anterior margin Argas 



Capitulum under a l)eak-like ])rojeetion, close to anterior margin Ovnilliodovon 



It is to the genus Argca^ that the famous Miana Bug of Persia belongs 

 {A. perx/cux). It lives in houses, and its puncture was declared by the 

 early travelers in those regions to produce startling results; convid- 

 sions, delirium, and even death following its attack. Si)ecimens kept 

 in Europe for experiment have failed to produce these dire conse- 

 quences, but there is such a wealth of testimony as to the dangerous 

 effect of the bite in Persia that possibly in that country the ]Miana 

 Bug may at times carry the germs of some disease. The European 



