82 M. 0. Strobelt on the Anatomy and 



(fig, 7), which are articulated in front of the eyes as already 

 mentioned, consist of five joints (antennce prceoculares, quin- 

 quearticulatce) ; they attain about half the length of the head. 

 At the articulation the first joint is 0*073 millim. in width ; 

 the last joint has a breadth of 0*035 mi Him. ; the lengths of 

 the individual joints are as follows : — first joint 0*062, second 

 0-064, third 0'048, fourth 0*045, and fifth 0-032 ; total 0-251 

 millim. 



All the five joints are beset with hairs, the length of which 

 shows great differences in the same antenna, while their posi- 

 tion seems to be constant in different individuals. The fifth 

 or terminal joint has its apical surface sharply marked and 

 oblique (fig. 7) ; and from it rise some small peculiar bacilli 

 with rounded ends. There are also on the different joints 

 variously formed chitinous plates and thickenings of the epi- 

 dermis. 



The eje, as in all lice, is simple. It consists of a strongly 

 convex cornea; behind this we find a clear layer, which 

 appears like a number of closely approximated vesicles with 

 gelatinous contents. Immediately behind this follows a 

 reddish-brown pigment-layer. Nothing could be seen of any 

 lens. The size of the eye is about 0*048 millim., and its 

 distance from the sheath [of the rostrum] about 0*305 millim. 

 As regards the position of the hairs on the head, as also upon 

 the rest of the body, the figure (fig. 1) will furnish informa- 

 tion. 



The thorax is quadrangular, with rounded anterior angles, 

 rather broader than long, and considerably broader than the 

 head (0*329 millim.). The pro-, meso-, and metathorax are 

 closely amalgamated, so that it is impossible to determine their 

 boundaries. On both sides of the thorax, towards the ven- 

 tral surface, are the sockets {acetabula) in which the legs are 

 articulated. These sockets are oval ; and in the first two on 

 each side their longer axis is perpendicular to the median line 

 of the whole animal, while in the hinder ones on each side it 

 forms an angle of about 60°. All the three acetabula are 

 united by a chitinous thickening with the chitinous band 

 which, on the underside, runs in a curve on each side from 

 the middle of the thorax to the anterior angles. The first 

 socket is smaller than the other two, just as the anterior pair 

 of legs is also considerably inferior in thickness to the two 

 hinder pairs (fig. 1). The thorax has further, on each side, 

 turned towards the ventral surface, a stigma, placed at the 

 level of the middle pair of legs, and therefore, as in all the 

 species of the genus Hcematoptnus which have been investi- 

 gated, belonging to the mesothorax, while in the genera 



