I. ricinus 



151 



Venter: vulva between coxae IV; spiracles circular, genital grooves 

 only slightly divergent, anal grooves rounded in front, parallel behind 

 anus. Capiiulum long (800 ft). Base pentagonal with parallel sides 

 and concave posterior border ; no cornua ; slight auricular ridges on 

 its ventral surface. Porose areas piriform, the broader end internal, 

 situated near the posterior border, the interval equal to their lesser 

 diameter (see Fig. 143, exaggerated in Fig. 144). Palps long, article 2 

 nearly twice as long as broad, impressed dorsally, article 3 distinctly 

 shorter than 2, rounded anteriorly. Hypostome long, with sides nearly 

 parallel, dentition 3 j 3, about ten sharp teeth per file, the external 

 the stronger. Legs : slender ; coxae as in the </ ; tarsi long, tapering 

 gradually. 



Nymph (PI. IV, Fig. 4, Text-figs. 145, 146): with the charac- 

 teristics of the $ , except that the lateral angles and the grooves of the 

 scutum are more pronounced, and the postero-lateral angles of the basis 

 capituli more pointed. The internal spine on coxa I is short, but 

 distinct. 



Fig. 145. I. ricinus o : dorsum and venter, x 30. (Nuttall, 1908, Fig. 5, 

 G, H.F.N, del,) 



