P. A. Buxton 
121 
it is removed from its burrow, but it is difficult to believe that they point in 
this direction when the mite is actually burrowing. On the side of the body 
there is a fairly long lateral seta (L 2) situated on a level with the posterior 
bare area. Warburton (l.c. p. 273) says that this is the “tasthaar' 1 of Fursten- 
berg, but that author states (p. 181) that he uses this term to include all the 
larger setae of the body and legs. This seta differs from all others in that its 
origin is from a short but definite papilla. The base of the seta L 2 is latero- 
ventral, but the tip can be seen from above. On each side of the anus are two 
anal bristles; the median pair A 1 are longer and stouter than the lateral 
pair A 2; the median pair are strictly terminal, the lateral, distinctly on the 
dorsal surface, close to the edge of the body. It is difficult to say which are 
Munro’s first pair of notothoracic bristles; if a they lie just below the camero- 
stome” it is not easy to see why he attributes them to the dorsal surface at all. 
Fig. 4. Sarcoptes scabizi var. equi. Copulatory papilla of an adult female; the copulatory duct is 
visible through the integument and is shown with a dotted line; cd, copulatory duct; cp, 
copulatory papilla; r, ridges on the integument. 
Immediately in front of the anus is an extremely minute papilla per¬ 
forated by a fine tube which opens upon its summit. The papilla (cp, Fig. 4) 
itself is scale-like, flat and very freely moveable. The tube or copulatory duct 
(cd) passes from the summit of the papilla through its base, and penetrates 
deeply into the body. It appears to have a chitinous lining and can be traced 
for some distance, and it can be seen that it becomes gradually wider and wider. 
I shall return to a discussion of its function when I describe the male genitalia 
(p. 138), and the immature female (p. 139). 
The papilla was first observed so long ago as 1861 by Gudden, who wrote 
an exceedingly interesting paper, dealing among other things with the internal 
and external genital organs of Tyroglyphus and Sarcoptes. He chose Tyro- 
glyphus by reason of its larger size, and when he had familiarized himself with 
its internal anatomy he turned to Sarcoptes. He figures the whole genital 
tract of an adult female; it consists of the papilla, as I have described it, a 
narrow tube leading from it to a spherical spermatheca, and two divergent 
ovarian tubes which pass from the spermatheca to unite immediately behind 
