20 ACARIDEA. 
begins near the white eyes and ends in about the middle of the lateral margin. In the 
hinder part of the body the intestines shine through the semipellucid skin in the form 
of blackish spots and stripes. On the interstices between the furrows of the posterior 
margin there occur alternating pairs of black and white linear stripes. The arrange- 
ment of the white colouring is subject to individual variation. Colour and shape of the 
frontal plate, of the rostrum, palpi, and legs, similar to that of the female, except the 
two frontal dimples, which only occur in the female and are wanting in the male*. 
The genital plate bears a transverse narrow fissure. ‘The anal plate bears two sete on 
each side of its posterior margin. 
2. Body oval, in empty specimens much depressed, in the satiated ones globose. 
‘Occipital plate triangular, almost reaching the centre of the dorsum, shining, testaceous, 
with dark brown side margins. From the posterior angle, which is yellowish-white, 
there proceeds a ramificated branch of the same colour towards the anterior margin of 
each side: these branches vary much in the different specimens; in some they are 
broad and continuous, in others they are narrow and tend to resolve themselves into 
several spots. The abdomen is dark brown, opaque, lighter at its margin, irregularly 
dimpled and furrowed, and bears short, thinly set whitish hairs. In transparent light 
under the microscope the ramifications of the intestines are visible in the form of 
blackish arcuate stripes. In the specimens which are filled with blood the abdomen 
assumes during life a uniform dark purple hue. The stigmatic plate in both sexes is 
triangular, its fissure claviform; the stigma proper presents itself as an arcuate small 
hole in a dark chitinized lamina. The genital plate is triangular, with a narrow 
transverse fissure, the anterior margin of which is finely denticulated. The anal valvula 
of each side shows two sete on its anterior and three on its posterior end. The front 
plate bears two round dimples. The eyes are white. The palpi are compressed, 
similar in colour to the body; they bear at the top of the second and the base of the 
third joint a small brown spot, and are beset with several short hairs; the fourth joint, 
which is very small, is inserted centrally at the top of the third one. The rostrum is 
of a light transparent brown, yellowish at its extremity. The mandibles bear five hooks 
arranged on two branches, the first bearing the first and second hooks, the second bearing 
the third, fourth, and fifth hooks; the second hook is very short and forms a sort of 
small appendage to the first one. The maxillary teeth are conoid, obliquely erect, 
somewhat distant from each other, amber-yellow. The legs are light brown, whitish 
at the apex of the joints; the first pair have their last joint irregularly denticulate at 
its apex, and the other pairs bear two teeth at the apex of the fifth joint. 
This species is the most common of all the Ixodide of Central America, and 
generally known by the name of “ garrapata,” which is a corruption of “ agarrapata ” 
(clasping something with the legs). I have never found the male in a parasitic state, 
* They have been drawn by mistake in fig. 2 of Tab, XII. 
