L. E. Robinson and J. Davidson 
45 
A minute segment, the caruncle (car.), forms a connecting link between 
the tarsus and the pulvillium proper. A curious feature is the presence 
of a roughened patch on the internal surface of each of the claws. This 
is not found in the nymphal or adult stages, and is doubtless associated 
with the different habit of life which is exhibited by the larva. 
EXPLANATION OF PLATES I TO VI. 
PLATE I. Argas persicus. 
Fig. 1. Female; dorsal surface, x 8 diameters. 
Fig. 2. Female ; ventral surface, x 8 diam. 
PLATE II. Argas persicus. 
Fig. 3. Female ; entire cuticle of dorsal surface, x 14 diam. 
Fig. 4. Female; entire cuticle of ventral surface and appendages, x 14 diam. 
PLATE III. Argas p)^>'sicus. 
Fig. 1. Female ; portion of dorsal cuticle showing scutellae and two discs, x 170 diam. 
Fig. 1 a. Female; scutella in transverse section, x 170 diam. 
Fig. 2. Female; portion of dorsal cuticle showing marginal scutellae, discs etc., 
X 170 diam. 
Fig. 2 a. Female ; two adjacent discs in transverse section, x 170 diam. 
Fig. 2 b. Female; marginal scutella in transverse section, x 170 diam. 
Fig. 3. Male; portion of venter, showing genital aperture, coxae etc., x 16 diam. 
Fig. 4. Female; portion of venter, showing genital aperture, coxae etc., x 16 diam. 
Fig. 5. Female; anus, x 170 diam. 
Fig. 6. Female; left spiracle (opaque preparation), x 170 diam. 
Fig. 7. Female; portion of venter, with capitulum depressed to expose opening of 
Gene’s organ, x 30 diam. 
PLATE IV. Argas persicus. 
Fig. 8. Female; capitulum, ventral, x 150 diam. 
Fig. y. Larva; capitulum, ventral, x 190 diam. 
Fig. 10. Larva; capitulum, dorsal, x 190 diam. 
PLATE V. Argas persicus. 
Figs. 11-20 {A-K). Male; transverse sections through the capitulum, showing the 
relations of the external and internal chitiuous structures. The levels at which 
the individual sections pass through the capitulum are indicated hy the letters 
A-K (see FI. IV, fig. 8, and PI. VI, fig. 21), x 110. 
PLATE VI. Argas persicus. 
Fig. 21. Female ; buccal cavity, in optical section, to show relations between hypostomal 
gutter, pharynx, salivary ducts, etc., x 200. 
Fig. 22. Male ; ohelicera, right, ventral aspect, x 350. 
Fig. 23. Male ; chelicera, right, lateral aspect, x 350. 
Fig. 24. Female; chelicera, right, ventral aspect, x 350. 
