DISEASES CAUSED OR CARRIED BY MITES AND TICKS 409 



acariasis in the squirrel. Laminosioptes cysticola produces a calcareous 

 cyst in the subcutaneous tissues of chickens. 



GENERAL EFFECTS OF TICK BITE. The mites in attacking 

 a host usually attack in numbers, or if individually, will be found to 

 burrow into the skin, but the ticks merely attach themselves to the skin 

 and draw blood. Tick bites are very likely to cause a PRURITIS which 

 in some cases will be painful for months or sometimes years. This is 

 especially true in the case of Argas reflexus (Fabricius) Latreille which 

 causes a painful bite marked for years by a cicatrix at the site of the 

 attack. Argas hrumpti Neumann causes a pruritis the site of which 

 remains indurated for years. The bite of Ornithodoros coriaceus Koch 

 is very painful; the bites are slow healing. The bite of Ornithodoros 

 turicata (Duges) Neumann may cause dermatitis and lymphangitis. The 

 bite of Ixodes ricinus (Linnaeus) Latreille may cause in man abscesses, 

 edema, lymphangitis, and fever; it may penetrate beneath the skin and 

 produce a tumor. The bite of Ixodes (Ceratixodes) putus (Picard- 

 Cambridge) Neumann is painful to man. It normally attacks birds. 

 The bite of the "conchuda," Ixodes bicornis Neumann, is sometimes fatal 

 to infants. 



TICK PARALYSIS. The bite of certain ticks causes paralysis of 

 man and animals. The NORTH AMERICAN HUMAN TICK 

 PARALYSIS is caused by the same tick which causes Rocky Mountain 

 Spotted Fever, Dermacentor andersoni Stiles (venustus Banks) ^ in the 

 northwestern States, and British Columbia, but a case is recorded from 

 California caused by Ornithodoros coriaceus Koch. Todd has described 

 a typical case of paralysis in children as follows : an active and appar- 

 ently healthy child suddenly develops a paresis or paralysis of the legs ; 

 neither abnormal temperature nor any other symptoms of paralysis is 

 constant. After the discovery of the tick and its removal the symptoms 

 disappear in a few hours with a possible exception of a more or less 

 local reaction, often probably due to a secondary bacterial infection at 



^ In view of the contention of Mr. Bishopp that venustus is the name of the fever 

 tick it is necessary to give my reasons for tlie adoption of andersoni. 



Dermacentor venustus Marx in Neumann (1897) is cited as an undescribed synonym 

 of D. reticulatus Fabricius. 



In 1905 Stiles named the Rocky Mountain Spotted Fever tick as D. andersoni, 

 strengthening his description in 1908 and 1910. 



In 1908 Banks drew up the description, as a new species, of Dermacentor venustus 

 (Marx) from the Marx material, which was subsequently examined by Stiles and 

 found to consist of three lots of material of at least two species. Stiles definitely 

 picked from Banks' type material Marx No. 122 as type of species D. venustus. Since 

 both Marx and Banks confused more than one species and neither designated a type 

 from the material, Stiles' tyjie designation is valid. 



In 1910 Stiles diflferentiates between the two species andersoni and venustus. 



Even if he should be found to be wrong in considering these as two species, 

 andersoni antedates venustus. But in order to set this question at rest an appeal has 

 been made to the International Commission of Zoological Nomenclature for a ruling 

 on the name of this tick. (W. D. Pierce.) 



