JAMESONIA. 



[ 445 ] 



Char. Palpi canaliculate, sheathing the 

 rostrum; mandibles three -jointed, basal 

 joint internal, the second joint external and I 

 long, the third short, denticulate ; labium 

 covered with reflexed teeth ; body very ex- 

 tensile, furnished near the rostrum with a 

 dorsal horny shield; legs with two claws 

 and a caruncle. 



These animals form part of those which 

 are popularly known as ticks. They are com- 

 monly found in dense woods, upon brush- 

 wood, briers, &c., from which they get upon 

 animals, as dogs, oxen, horses, &c., burying 

 the rostrum deeply in the skin and sucking 

 the blood, so as to become distended to ten 

 times their original size. They are also 

 found upon reptiles, birds, and occasionally 

 attack man. 



Haller points out two foramina at the 

 hinder margin of the last joint of the first 

 pair of legs, covered with a membrane, and 

 with otoliths, forming an auditory apparatus. 



The species are very numerous, and have 

 been arranged in several genera by some 

 authors. The following are the commonest 

 species : 



I. ricinus, the dog-tick. Body oval, in 

 the gorged condition becoming globular and 

 blackish violet ; legs and appendages brown. 



I. reduvhis. Pale yellowish red; head 

 and legs black. Found upon sheep. 



1. pictus. Back white, with brown 

 spots; crenulate posteriorly; legs brown. 

 Found upon deer ; also upon mosses. 



I.Ijvgesii (pfofnfetttyDug.) (PI. 6. figs. 19- 

 22). Oval, leaden grey, without spots. 

 Found upon dogs. 



I. plumbeus, Leach. Shield heart-shaped, 

 slightly rugose ; rostrum, palpi, and legs 

 pale ferruginous ; body of a leaden colour ; 

 lenglh 1-4". Found upon and in the nests 

 of the bank-swallow (Hirundo riparia). 



BIBL. Gervais, Walck. Apter es, iii. 234 ; 

 Hermann, Mem- Apter. ; Duges, Ann. Sc. 

 Nat. 2 ser. ii. ; Leach, Linn. Tr. xi. ; Koch, 

 Uebers. ; Denny, Ann. N. H. 1843, xii. ; 

 Gene, ibid. 1846, xviii. 160; Macalister, 

 Qu. M. J. 1871, 166 ; Murray, .Ec. Entom. ; 

 Megnin, 121 ; Haller, Zool Anz. 1881, 165 

 (Jn. Mic. Soc. 1881, 449). 



J. 



JAMESO'NIA, Hk. A genus of Gram- 

 mitideae (Polypodiaceous Ferns). Cne 

 species ; Andes. (Hooker, Syn. Fil. 369.) 



JA'NIA, Lamouroux. A genus of Coral- 

 linaceae (Florideous Algae), calcareous fila- 

 mentous bodies, occurring in tufts, pale red j 



or purplish when fresh, on small Alga3 be- 

 tween tide-marks. The filaments are arti- 

 culated, dichotomously branched, and im- 

 pregnated with a calcareous deposit. The 

 fruit consists of urn-shaped ceramidia, 

 formed out of the end joints of the branches, 

 a dichotomous continuation of which is re- 

 presented by a pair of minute divergent 

 horns on the ceramidium ; the latter has a 

 pore at the apex, and contains a tuft of erect 

 linear tetraspores. British species : 



J. rubens. Joints of principal branches 

 cylindrical. Harvey, Phyc. Brit. pi. 252. 



J. corniculata. Joints of principal branches 

 obconical and compressed, /. c. pi. 234. 



BIBL. Harvey, /. c.. and Mar. Ala. 107. 

 pi. 13 D. 



JAT'ROPHA. See CASSAVA. 



JONESIA, G. S. Brady, 1865. A 

 marine Ostracode. See BYTHOCYTHERE. 



JONESIEL'LA, Brady. A genus of 

 Copepodous Entomostraca. 



Two British species; in dredgings. 

 (Brady, Copep., Ray Soc. ii. 38.) 



JULTJS, Linn. A genus of Chilopodous 

 Myriapoda. J. terrestris and a few other 

 species are often found in gardens. 



JUNGERMANNIA, Dill. A genus of 

 Jungermanniese (Hepaticas). Fructification 

 terminal. Perichastial leases free or united 

 only at the base, like or unlike the stem- 

 leaves. Perigone membranous, tubular, 

 plaited-denticulate at the apex, the mouth 

 three- or six-cleft. Vaginule membranous, 

 included or rarely exserted. Capsule four- 

 valved, splitting to the base. Amphigastria 

 present or absent. 



This is the largest genus of the Junger- 

 mannieae ; among the commonest species 

 are J. bicuspidata, L., J. albicans, L., J. bar- 

 bata, J. setacea, &c., found on wet bogs, 

 banks, rocks, &c. 



BIBL. Hooker, Br. Jungerm.) Br. Flo?\ 

 i. pt. 1. 112, &c. ; Ekart, Synops. Jungerm. ; 

 Nees v. Esenbeck, Europ. Lebermoose ; 

 Gottsche, Lindenberg, and Nees, Synops. 

 Hepatic., Hamburg, 1844-47 ; Stephani, 

 Jungerm. (Germ.) 1879. 



JUNGERMANNTEJE. A family of 

 Henaticse, distinguished by possessing a 

 distinct stem, bearing leaves, often with 

 stipule-like bodies called amphigastria (fig. 

 380), with terminal archegones, and spo- 

 ranges bursting by four valves (figs. 320 

 and 321), destitute of a columella, contain- 

 ing elaters mixed with the spores. 



The British genera may be grouped as 

 follows : 



