212 A>i)i<ils Eiito)}iological Society uj America [\'ol. III. 



tarsus; genual slightly over one-third as long as the tibia; femur 

 as long as tibia; coxa almost completely hidden in its socket 

 (Fig. 4), where it has a double hinge upon which it rotates. 

 Second pair of legs (Fig. 5) shorter than the first and normally 

 bent at the genual; tarsus of leg II almost as broad as long; tibia 

 much broader distally than proximally; genual slightly longer 

 than broad; femur of a very peculiar shape, being much flat- 

 tened, with an expanded latero-ventral margin; coxa as in leg I. 

 The last two ])airs of legs are of the common type; the last ex- 

 tending slightly beyond the tip of the abdomen. Ungues tri- 

 dactyle; dactyles equally developed. Length 0.42 mm. ; breadth 

 0.22 mm. 



I have examined the mouth-parts of this species in hope that 

 they would show some peculiarities, especially since this species 

 has a rather extraordinary habitat* but they present the typical 

 acarid form (Fi.L,^ 1); however, they are somewhat weaker than 

 usual. The mandibles (Fig. 2) appear to be normal. The 

 internal anatomy presents no special peculiarities. The organs 

 are less compact than in the common species, as would be ex- 

 pected, because of the drawn-out form of the body. The ven- 

 triculus. or stomach, and its caeca appear to be rather small, 

 but this is probably due to the shrinking of the tissues. In the 

 females often there can l)c seen several large developing ova. 

 The ovipositor is rather longer than usual. 



ExpLAXAiiDN oi" Pl\ti-: XXIX. 



Mouth-parts as seen from below. 

 Side view of one of the mandibles. 

 \'entral surface of the body. 



The coxa; of legs I and II as seen fn m hclcw, so as to show their double- 

 hinged arrangement. 

 Inside of leg II. 

 Tarsus and til)ia of leg I. 



