ORDER ACARINA : THE TICKS 281 



begins to feed at once if it can, remaining attached to its 

 victim for several days, like an Ixodine. In warm weather 

 the larva may moult into the first nymph stage in about 

 eight days after leaving its victim, but in Nuttall's experi- 

 ments in spring-time, in England, the time taken was more 

 than six weeks. If the nymph can feed at once it may 

 transform into the next, or deutonymph stage, in two or three 

 weeks ; and some weeks later — ^provided it finds food — the 

 deutonymph becomes adult. In Lounsbury's experiments 

 in South Africa the complete life-circle, from egg to egg, 

 occupied about ten months ; so that adults may live some 

 time before they begin to generate. A larva kept unfed 

 dies, according to Lounsbury, within eight weeks, but unfed 

 nymphs are said to be able to live for at least a year, and 

 unfed adults for more than three years. 



Argas reflexus (Fabr.). This species differs from A. 

 persicus in having the front end of the body more sharply 

 narrowed, the margin finely striated, and the basis capituli 

 as long as broad. It is found on poultry, but has a pre- 

 dilection for pigeons and is a known inhabitant of pigeon- 

 cotes ; it also may attack man. Its geographical range 

 according to Neumann, includes Europe, North Africa, and 

 North and South America. Its bite may be fatal to pigeons, 

 and may cause much local inflammation in man. 



Ornithodorus, Koch {opvi^ = a bird ; (Sopoj = a leather bag). 

 Body either flattish or rotund, commonly oval or oblong, 

 often with the front end narrowed or pointed, its margin thick 

 and not specially defined in any way. Integument mammil- 

 lose or papillose ; coxal folds usually conspicuous ; constant 

 pre-anal and post-anal furrows present. Capitulum inferior, 

 but the tip of the pedipalps may be visible in a dorsal view. 

 Eyes, when present, two pairs, situated on the supracoxal fold. 



Neumann recognises twelve species as valid. 



Synopsis of Species of Ornithodorus (after Neumann). 



Hypostome unarmed ; integument in nymphal stage (and in places 

 in the adult stage) spinulose ; lateral constrictions between 

 cephalothorax and abdomen very distinct O. inegninii. 



Hypostome armed with recurved teeth as usual ; integument not 

 l spinulose = 2. 



