148 



Genus Ixodes 



convex when gorged. Marginal fold slight, generally of lighter colour 

 than the scutum. Scutum (average 18 x 1*1 mm.) glossy with very 

 numerous fine punctations ; cervical grooves very superficial ; lateral 

 grooves absent, or their commencement faintly indicated. Numerous 

 fairly long scattered white hairs. Emargination moderate, scapulae 

 blunt. Venter: genital orifice large, between coxae III; pregenital 

 plate nearly twice as long as broad ; median plate fairly broad with 

 rounded sides, anal plate with lateral borders divergent, adanal plates 

 narrowing posteriorly. Spiracles large, oval, with long axis directed 



Fig. 139. I. ricinus & : venter and dorsum, x 30. Specimen from Coilessan, Scotland. 

 (N. 933. Nuttall, 1908, Fig. 7, G. H. F. N. del.) 



10x6-4 mm., by Wheler. Neumann states that the unfed ? measures 4x3 mm., the 

 gorged ? from 10 x 6 to 11 x 7 mm. Two of the most replete specimens in our collection 

 measure 10 x 7'5 and 10-5 x 6-5 mm. respectively. Nymphs, unfed, measure l - 5 x 1-68 mm., 

 when gorged they attain 3-3 mm. in length (Wheler, 1899, p. 49). 



