ARACHNOJDEA. 577 



Feet gressorial, with coxae scarcely distant, unguiculate, not pro- 

 vided with a vesicle or acetabulum. 



Oribata LATE. (Notaspis HERMANN). 



Sub-genera : HopopJiora KOCH, Galumna V. HEYDEN, GERV. 

 (Pelops KOCH, Oribates and Zetes ejusd.), Damceus KOCH, (JBelba 

 V. HEYDEN), Nothrus KOCH. 



Consult OLIVIER Encycl. method., Ins. vm. pp. 530 534. Most of the 

 species live in mosses on the trunks of trees ; in some the body is girdled 

 by a lamella produced on each side ; Acarus marginatus DE GEEK Mem. 

 vn. PL vm. fig. 6, Notasp. humeralis HERM. Mem. Apt. PL 4, fig. 5 ; 

 Notasp. alatus HERM. PL 4, fig. 6, &c. 



Family V. Ixodea. Body defended by a coriaceous, extensile 

 >vering. Palps sheathing rostrum, with four joints ; rostrum por- 

 ct, truncated, composed of two lateral parts (mandibles?), denti- 

 ulate at the apex, and a middle part (labium) covered with nume- 

 us recurved barbs. Feet with last joint armed with a caruncle 

 vesicle, and with two claws. 



Ixodes LATE. 



Sp. Ixodes ricinus, Acarus ricinus L., DE GEER Mem. vii. PL 6, figs, i 8, 

 LYONET Recherch. PL 6, figs, i 8, Tick, Louvette ; these animals live in 

 woods, and attach themselves (the female) to different animals, especially 

 to dogs ; from sucking the blood the body swells in form of a pea. The 

 female is nearly 5'" long ; the male, much smaller, on copulating attaches 

 itself beneath the abdomen of the female by means of the sucker, at the 

 base of which the vasa deferentia open, to the vulva, situated at the fore- 

 part of the body between the first and second pairs of feet. This singular 

 copulation was already figured by DE GEER ; see also P. W. J. MUELLER 

 in GERMAR u. ZINCKEN Magaz. der Entomol. n. 1817, s. 278 289. 

 When laying her eggs, the female, according to the observations of FRISCH, 

 gives out a clear fluid from her mouth, for fixing to her body the eggs, 

 which the animal advances to her mouth ; hence the erroneous opinion of 

 CHABRIER that the eggs are laid through the mouth. 



Ixodes americanus, Acarus niguaT)E GEER Mem. vii. PL 37, figs, u 13. 

 Compare G. E. TREVIRANUS, Zeitschr. f. Physiol. iv. n. s. 185 191, Taf. 

 xv. xvi. (probably Ixodes crenatus KOLLAR). This and other allied species 

 known in America by the name of Piques are very distressing, and some- 

 times dangerous to man and cattle. 



By the presence or absence of eyes (which are wanting in Ixodes ricinus), 

 and some other characters, KOCH has divided this numerous genus into 

 several others. See ERICHSON'S Archiv f. Naturgesch. 1844, s. 217 239, 

 and Uebersicht, 4tes Heft, 1847. 



