60 ANIMAL PARASITES. 



cut em hominum, aut animalium pratereuntium et adeo ad cutem 

 serpentum, festudmum, fyc., transeunt. 



1. Ixodes Ricinus, the common Wood-Tick = the Dog's Tick, and 

 also perhaps the Egyptian Tick (fig. 9.) 



Martiny describes it as oval, yellowish blood-red, thorax 



darker, abdomen finely hairy, with 

 Fi S- 9 - the lateral walls bent upwards. The 



females, which are only V" in length, 

 become of the size of a hazel-nut by 

 sucking. A good figure of the parts 

 of the mouth of the Egyptian tick is 

 given in Poppig's ' Illustrirter Natur- 

 geschichte/ iv, p. 53, fig. 2845. The 

 common tick is here represented 

 after Gurlt. The line at the side in- 

 dicates the natural size. 



2. Ixodes marginatus = the Margined Tick, 



According to Martiny, longish, obovate, flat, brown, shining, 

 with separate short hairs. Female 1'", becoming as large as a 

 pea by suction. 



3. North and South American Ticks = locodes Americanus, 

 I. ImmanuSy I. crenatus. 



They occur in the woods of these countries, frequently in ex- 

 traordinary quantities, and almost epidemically, and possess 

 various local names, for example, wood-louse = Pou de Bois in 

 Pennsylvania, Nigua in Carthagena, Pique in Peru, and Carabatos 

 in Brazil, in all parts of which, according to Martiny, they are a 

 great plague to men and animals. The particular species are 

 but imperfectly known and distinguished. 



All the species are particularly attached to dry, sunny woods, 

 thickets, or hills, and avail themselves of every opportunity of 

 getting upon animals. Imperceptibly they immerse their pro- 

 boscis in the skin, often in very sensitive spots, and often remain 

 for days hanging to the place where they have bitten in, held fast 

 by the retroverted teeth of the surfaces and margins of the pro- 



