SEVENTEENTH ANNUAL REPORT. 



467 



surface pentagonal, as broad in front as long, summit anterior, lateral borders con- 

 vergent in back. Porose areas elongate transversely. Mandibles 1.5 mm. long, digit 

 150 the sheath of the stem very shagreen ed, granular. Internal apophysis of 

 « digit elongate, with two retrograde teeth, one terminal, the other on the middle of the 

 length, with a long stem of insertion terminated toward the posterior fourth of the 

 digit; external apophysis with 5 teeth, increasing in size from the anterior to the pos- 

 terior, the latter being strong. Hypostome elongate, lanceolate, provided on each 

 half, besides the small teeth at the summit, with three more or le js regular rows of 

 well developed teeth: One row lateral and marginal, with strong, sharp teeth, the 

 anterior and posterior smaller; one intermediate, with smaller teeth; and a median 

 row scarcely extending beyond the anterior half. Palpi 800 long (100 yu, 360 

 340 yM, from first to third), digits depressed dorso-ventrally, dorsal surface flat, ventral 

 surface excavate in an internal bevel; dorsal surface provided with sparse hairs, in a 

 series on the median border of the ventral marginal thickness. Legs thin. Coxae 

 elongate, contiguous in the young, slightly separated in the replete; coxse I prolonged 

 on their postero-median angle by a strong spine, which strikes against coxae TI. All 

 the articles provided with stiff hairs. Tarsi long and thin, forming, especially tarsi 

 I, nearly a third of the length of the leg, attenuate gradually without protuberance; 

 pulvillum nearly as long as the nails. 



Nymphs and larvae have a capitulum which recalls that of the female. 



Fig. 227.— Dorsal and ventral views Of digit of mandible of male and of female Ixodes ricinus. X 195. 

 After Neumann, 1899, p. 114, fig. 1. 



The above description is taken almost verbatim from Neumann, 

 who has all of our specimens of this tick with the exception of a few 

 females. 



The castor-bean tick is reported from sheep, goats, cattle, horses, 

 deer, dogs, cats, fox ferrets, hedgehogs, hares, rabbits, bats, birds, 

 and various other animals, including man. It is found in Europe, 

 North Africa, and North America, and it is one of the oldest and most 

 commonly known ticks. 



European Dog Tick {Ixodes hexagonus) 

 (Figures 228-235.) 



Specific diagnosis.— 7a7o<ies; Male—Bodj elliptical, almost as broad anteriorly 

 as posteriorly; length 3.5 to 4 mm., breadth 2 to 2.5 mm. Brown red, legs lighter. 



^ Synonymy and Bibliography. 



. 1815: Ixodes hexagonus Leach, 1815, p. 397; type host, Erinaceus europxus, England.— 

 Gervais, 1844, p. 240.— Koch, 1844, p. 234.— Idem, 1847, p. 23.— Canestrini, 



