Bd. V: II) THE ACARI. 5 



one small tooth in the middle. Calcar mandibuli rather broad, of even width for 

 the greater part of its length, at the end pointed and curved slightly upward; 

 exactly as long as the upper jaw. 



The upper jaw a little longer than the lower one, not so strongh' curved at 

 the end; in the distal half three small teeth, increasing in length towards the back; 

 the posterior one opposite to the middle tooth of the lower jaw. 



To judge from the shape of its mandibles and the 2nd pair of legs, the present 

 genus is most closely related to Gainascllus Berl.; but on the other hand the shape 

 and the texture of its dorsal shields are features, only to be met with in other 

 subfamilies of the Parasitidœ, and the shape of the first pair of legs is a quite 

 unparallelled feature. 



Locality: No. \2. One male. 



2. Trachygamasus(.^) Ohlini nov. spec. 



(PI. II, fig. 17. ri. Ill, fig. 9, text-figf. 3— lo.l 



This species will most probably prove to be the type of a new genus. As, 

 however, only one single nympha has as yet been found, I consider it more 

 appropriate to refer it for the time being to the genus Tyachygamasns, to which it 

 appears to bear the greatest resemblance in some essential respects. Above all the 

 peculiar shape of the ambulacres of the first pair of legs, which is common both to 

 the present nympha and that of T. piisillits (the only known species) is to be taken 

 into consideration, as thisis, according to Berlese [4. p. 117.], a feature, otherwise not 

 met with amongst the Parasitinœ; on the other hand the peritremata, being very 

 short, resemble much those of the genus Podolcelaps Berlese described on a single 

 nympha from Matto-Grosso in Brazil [2. p. 207, tab. IX, fig. 3] and the narrow, 

 slender mandibles bear the greatest resemblance to the genus Iphis (Emœiis). 



Length (excl. capitulum) 0,61 mm. Breadth 0,4 mm. 



Colour, very light straw-yellow. The shape oval, pointed posteriorly. 



The dorsal side. (PL III. fig. 9.) I have not been able to detect any distinct 

 dorsal shields, but on a level with trochanter IV, there seems to be a transversal line, 

 dividing the cuticle in two parts, one greater anterior and one smaller posterior one. 

 The dorsal side is provided with numerous, regularly placed, bare bristles of which 

 4 pairs are about twice as large as the others and placed as follows: one pair, 

 directed forwards, near the median line, close to the anterior margin, the second pair 

 nearer the side equidistant from the middle and the lateral margin and on a level with 

 the anterior edges of coxae II; the third pair is still nearer the side and on a level 

 with the posterior edges of coxa: II; the fourth pair is inserted straight behind 



