72 



Genus Ornithodoros 



well marked. Spiracles circular, 250 fi in diameter, stigmal plate 

 semilunar (resembling Fig. 10). Anus : anal frame broader than long 

 (150 to 200 fix 200 to 250 /*), each valve provided with four short 

 hairs. Eyes absent. Integument (see Fig. 102) with small circular, 

 shallow pits (not mammillae) with short central hairs, the whole surface 



Fig. 102. 



Fig. 103. 



Figs. 102, 103. O. megnini <r , x 8. Dorsum and venter. From specimen, loaned by 

 Prof. Neumann, from New Mexico, U.S.A. Original, N. and W. 



Fig. 104. O. megnini. A, digit of nymph, 85 /j. 1. B, digit of ? , 75 /i I. 



being finely granular like sandpaper. Reticulate fossettes occupy the 

 ventral and dorsal depressions ; others scattered here and there. On 

 the ventral surface, between the two post-anal grooves, extremely small 

 and crowded spines. Capitulum very small and very short ; 150 yu. 

 (from base of palps to tip of hypostome). Chelicerae : see Fig. 104 B. 



