200 



27. Spiuturnix mystacina Klti. 



With Plate IX, fig. 32-37 and X, fig. 38-42. 



Embryo. — Length 640 (/.. — Colour white, with straw- 

 coloured hairs and peritreraa. I have dissected the embryo out of 

 the mother's uterus. The figures 32 and 33 represent them still 

 in their envelops. I have also cut the envelops, but the embryo 

 did noth stretch its legs, even after being treated with caustic 

 kali. 



Fig. 32 shows the embryo viewed dorsally. There are two dorsal 

 shields, a larger anterior and a smaller posterior one. Both are 

 without any markings, but provided with senseorgans (Fig. 34), 

 of which 5 pairs are visible on the anterior and 2 pairs on the 

 posterior shield. The anterior shield is subpentagonal; its posterior 

 edge is deeply excavated trapezoidally to receive the anterior 

 portion of the posterior shield. The shields are separate by a 

 narrow space. The dorsal side shows the following hairs : 4 pairs 

 before the anterior dorsal shield, 1 pair aside, 1 pair near the 

 stigma, 1 pair above coxae 4, 2 pairs behind the posterior shield. 

 The capitulum, the epistoma, the first joints of the palpi and 

 legs are visible beyoud the margin of the body. It is obvious that 

 the stigma is ventral; the peritrema first runs dorsally, forward, 

 and then ventrally between the coxae 2 and 3. 



Fig. 33 represents the embryo viewed ventrally. Remarkable on 

 this side are : the legs 1, 2 and 3 have already their definitive 

 position, i. e. quite close together, whilst legs 4 are still remote 

 a considerable distance; the legs 4 are not so far developed as 

 legs 1, 2 and 3, being still winkled. This is a proof that the 

 embryo passes through a larval stage with 3 pairs of legs, after 

 which stage it gets its nymphal pair of legs. The stigma is 

 ventral ; between coxae 2 and 3 the top of the peritrema is discer- 

 nable and a hole, the opening of the excretory organ. 



Protonympha. Length 730 ix.. Colour light straw-coloured. 



Fig. 35. The protonympha shows dorsally the two dorsal shields, 

 exactly like in the embryo, but provided with pits (Erosionsgruben 



