34 ANIMAL PARASITES. 



in length, aud J"' in breadth, with hairs and bristles ; under 

 the microscope, a truncated, tortoise-like oval, notched before arid 

 behind, flat on the belly and convex on the back. The skin 

 breaks with difficulty, and exhibits irregular segments, with margins 

 lying over one another posteriorly, which form a system of 

 parallel lines. On the back we see small, transparent cones, 

 or, more correctly, teeth, in several rows, which I have indicated 

 in the mite of the cat as file-teeth for boring the galleries, and also 

 near these some long, thin hairs, and on each side ten peculiar, 

 truncated, hollow processes, which are moveable, according to 

 Eichstadt, and of which the three anterior are shorter and thicker ; 

 the seven posterior, arranged in two rows, are longer, and, 

 according to Gudden, open at their extremity, but form little 

 rings at their base, in the cavity of which they are inserted with 

 a short stalk. It appears to me to be an optical illusion to 

 suppose them to be open. What purpose they serve, I do not 

 know; but they may, perhaps, be employed as organs of touch. 



The feet are supported by a yellow, chitinous framework, 

 attached to the belly. For the first pair of feet of the female 

 there is a single massive bearer (band or stalk), the common 

 simple stem of which runs in a straight line almost from the 

 middle of the animal towards the head. At a short distance from 

 the head this stem divides into a fork, and then forms a sort of 

 triangular framework for each separate basal joint of the first 

 pair of anterior feet. On each side of this straight stem, and 

 nearly in the same level with its hinder extremity, there originate 

 two massive bands (stems or bearers), convex towards the median 

 line of the animal, and concave externally, which bear the same 

 triangular framework at their anterior extremity, for the basal 

 joint of the foot of the second pair. 



The two hinder pairs of feet are also supported by a particular 

 horny framework. The third pair of feet is attached by a more 

 bowed stem, concave internally, convex outwardly, and furnished 

 on the outside with a small tubercular spine; from this the 

 triangular framework of the basal joint of these feet originates. 

 The last (fourth) pair of feet exhibits a short and straighter stem, 

 which runs obliquely from within outwards. It is characteristic 

 of the mature female that there is no transverse band between 

 the posterior pairs of feet. It would deprive the eggs of the 

 space necessary for their evolution, and render the extension of 

 the belly difficult or impossible. Each of the four anterior feet 



