318 ERNEST WARE EX. 



lie somewhei-e over the legs, and uieclianically this is more 

 advantageous than dragging a heavy burden from behind. 



Dorsal Surface. — Following Verhoeff's scheme it may 

 be said that there is no tergite to abdominal segment I ; but 

 a pair of spiracles (1st abdominal) occurs at the anterior end 

 of the stalk. 



Abdominal segment II has a highly modified tergite. It 

 consists of a median X-shaped sclerite bearing ventrally 

 betweeu the two arms on each side a veiy deeply-curved 

 chitinous plate embracing both the abdominal stalk and the 

 commencement of the upturned swollen portion of the 

 abdomen (PI. XVI, fig. 8). A spiracle (the 2nd abdominal)' 

 perforates the posterior portion of the arch. 



Abdominal segments III, lY, V and VI bear relatively 

 narrow tergites with a median ridge running from right to 

 left, and with pairs of spiracles wedged betAveen their 

 extremities and the abdominal longitudinal ridges (fig. 3). 



Abdominal segments A^II and VIII bear plate-like tergites,. 

 aud spiracles are absent. The chitin of tergite VIII is quite 

 thin and even diffuse in character. 



Abdomin.il segment IX is the last external segment; it 

 carries a wide, curved, spatula-shaped tergite, and there is a 

 conspicuous spiracle on each side (figs. 1 and 10, sp.). 



Abdominal segment X is telescoped into segment IX; in 

 the female it bears an obvious tergite which is richly 

 provided with bristles ; in the male this tergite would appear 

 to be absent, unless two U-shaped chitinous structures at the 

 base of the paramera or lateral lolies may be supposed to 

 represent it. In both sexes sternite X is represented by a 

 pair of setose plates. 



In most insects there are 8 pairs of abdominal spiracles 

 occurring in the first 8 abdominal segments, but in aker- 

 mani we find spiracles in abdominal segments I- VI and in 

 IX. This presence of spiracles in the 9th abdominal segment 

 is quite unusual, but in the present insect they are very 

 obvious structures and are perfectly clear in section. 



The less modified tergites, as those of segments III-VI,. 



