SCIENCE- GOSSIP. 



39 



(^1) Anal groove encircling anus in front. 



(a 1 ) IXODES Latreille, 1795. 



Synonyms : Acarus Linn., 1758 ; Cynorliaestes 

 Hermann, 1804 ; Crotonus Dumeril, 1822. 



Eyes absent. Palpi long. An ad-anal groove 

 open or closed behind, but encircling the anus in 

 front ; another long groove similarly encircles the 

 sexual organ in front and widens behind (fig. 6). 

 No terminal spine to the tarsi. Underside of the 

 male covered with shields or plates. Dorsal shield 

 of male covering the whole body with the excep- 

 tion of a margin. No indentations on the posterior 

 margin. The distended female has three dorsal 

 longitudinal grooves behind. Peritremes and 

 stis'mata circular. 



when fully distended. Basal joint of first pair of 

 legs with a long spine. Legs, shield, rostrum, 

 etc., dark brown to nearly black. Colour of body 

 deep orange red, showing four faint dark intes- 

 tinal lines behind the shield, lighter underneath ; 

 light grey in front both above and below. Pu- 

 bescent, opaque, and margined. When distending, 

 light red to reddish-grey, or even pure white ; fully 



Fig. 11. /. mlucim: Adult female. 



Fig. 12. /. eduvius. Adult male. 



distended, olive green, or dark red to black, with 

 irregular yellow streaks on the back and sides 

 when about to lay eggs. Sexual orifice opposite 

 fourth pair of legs. Male (fig. 12). Length about 

 2-35 mm. to 2-80 mm. Coxae of first pair of legs 

 with shorter spine. Body dark brown to almost 

 black, with brownish-white margin. Apparent 

 sexual orifice opposite third pair of legs. Eostrum 

 much shorter than that of female (figs. 8 and 9). 

 Shield oval. Anal shield small, about one-third the 

 length of the large ventral shield. 



Professor Neumann describes over sixty species 

 of this genus. One of the commonest in this 

 country, I. reduvius, is believed to be the carrier 

 of the " louping-ill " microbe, which causes heavy 

 losses amongst the sheep stock of the Borders and 

 Scotland. Sexual intercourse probably only takes 

 place on the host. 



Ixodes reduvius Linnaeus. 



Synonyms : Reduvuis Charleton, 1668 ; Ricinus 

 caninus Eay, 1710 ; Acarus ricinoides De Geer, 

 1778; A. reduvius Linnaeus, 1788; A. ricinus 

 Linnaeus, 1788 ; Ixodes ricinus Latreille, 1804 ; 

 Cynorliaestes reduvms Hermann, 1804 ; C. ricinus 

 Hermann, 1804 ; Ixodes meg athy reus Leach, 1815 ; 

 I. bipunctatus Risso, 1826 ; Cynorliaestes hermanni 

 Risso, 1826; Crotonus ricinus Dumeril, 1829; 

 Ixodes trabeatus Audouin, 1832 ; I. plumbeus Duges, 

 1834 ; I. reduvius Halm, 1834 ; I. fuscus Koch, 

 1835 (?) ; I. lacertae Koch, 1835 (?) ; I. pustularum 

 Lucas, 1866 ; Ifodiens Murray, 1877. 



Female (fig. 11). Length from about 3 mm. 

 when fasting to 10 mm. long by 6-50 mm. wide 



Fig. 13. /. reduvius 

 Nymph. 



Fig. 14. /. reduvius. 

 Larva. 



Nymph (fig. 13). Length, about 1-50 mm. fast- 

 ing to 3-00 mm. when replete. Body olive-white, 

 with four distinct brown posterior intestinal marks, 

 also similar anterior ones ; leaving a paler centre 

 to the shield shaped like an arrow-head. When 

 distending, opaque white to blue-black, and finally 

 black. 



Larva. Length, 0-80 mm. fasting to 1-43 mm. 

 distended. Body transparent, with olive-green 

 intestinal marks ; same colour as nymph when dis- 

 tending (fig. 14). 



It is parasitical on numerous hosts, of which the 



