174 Haemaphysalis punctata 
often referred to as the third apophysis : it is firmly fused to the internal 
article, a prolongation of the cavity of which extends into it, and we 
consider it to be simply an outgrowth of the latter, comparable to similar 
processes often seen on the homologous articles of the chelicerae in 
the Gamasidae and Oribatidae, and for this reason we prefer to term 
it the dorsal process (d.p.). The external article articulates with the 
expanded base of the internal article ; it consists of a flattened plate of 
chi tin, the external margin of which is deeply incised, so as to form a series 
of four or five pointed cusps, of which the terminal one is the smallest, 
and the proximal the largest: it is hollow and its internal cavity is 
continuous with that of the internal article; indistinct channels appear 
to run out from the central cavity for a short distance along the lateral 
cusps. In many cases, the cavity of the internal article appears to 
terminate in a minute pore at the distal extremity; whether this is 
actually the case we are not in a position to express a definite opinion : 
it is, however, certain that the interior of the expanded base of the 
internal article communicates with the exterior by at least two fine 
channels, one on the internal side and one on the external (pr.), the 
possible function of which it is difficult to imagine. 
The digit of the chelicera is surrounded on its internal side by 
a delicate hood of thin and very transparent chitin, a prolongation of 
the shaft of which it is a part; it is tapered away on the external side 
of the digit in such a manner as to fully expose the cutting parts of 
the appendage. The internal article bears on its basal portion a 
single serrate hair, which protrudes between the hood and the lancet- 
shaped portion of the former (see Text Figs. 7 and 9 and PI. XV, Figs. 
4—6). 
The base of the digit, formed entirely from the expanded portion of 
the internal article, articulates with the shaft by a rocker-like hinge- 
joint, the shape of the articular surfaces being such as to limit the 
movement of the digit to a horizontal plane. The movements of the 
digit are produced by the tendons, one internal and one external, which 
originate in the mass of muscle occupying the cavity of the shaft (see 
Text Fig. 6, p. 170): the internal tendon is inserted into the internal 
article at its proximo-internal angle, while the external tendon, the 
stouter of the two, runs partially round the lateral surface of the article 
and is inserted towards the upper surface of the expanded base. 
The palps. These appendages are inserted into the basis capituli 
at its antero-lateral angles. The general outline of each is that of a 
truncated cone; the basal portion is much constricted laterally, but not 
