( 556 ) 



others monnted flat in balsam. Wo employ a perforated slide with a thin loverslip 

 as a bottom on which the specimen rests, another coversli]) lying on top of the 

 specimen. Tliis method allows the insect to be studied ei|n!illy well from 

 both sides. 



The 27 specimens of the British Museum, which are now all transferred 

 into alcohol or mounted in balsam, represent, wo think, all the s])eoies which are 

 known of this family. 



As has already been clearly demonstrated by ^^peiser,* the PolijcteniJac are 

 nearly related to the Cimicidae. The agreement in the structure of these two families 

 of Tthjnrhofa is indeed so close that no other place could be assigned to the 

 Poly cteu ids than nearest to the bed-bugs. 



MoRrHOI.OGY. 



Our knowledge of the exoskeletou of these bat-parasites is mainly based on 

 Westwood's original tigures in Thesaiir. Oxon., wliich in beauty of drawing, as well 

 as in clearness of the detail necessary for the recognition of the species, far surpass 

 everything that has been published since on this family. However, the tigures 

 are not correct in every detail, chiefly owing to the state of preservation of the 

 specimens, and to the fact — always an important one — that the figures were the 

 first which illustrated the morphology of a type of insect until then unknown. 

 The internal anatomy of the Pobjctenidae has not yet been investigated. 



The most interesting features in these insects is the great modification of 

 the head and anterior legs, which are (|uite different from these parts in other 

 lUtynchoUt , the movable liuiiform clipeus osjiecially being a character of the 

 Pobjctenidae uniijue in tliat order. This clipeus is generally represented as being 

 separated from the head by a groove on the upper us well as the under side, 

 Waterhouse's figure of P. spasmae (1879) being an exception. In this figure the 

 under side of the head is drawn as being devoid of the dividing-groove, in which 

 the figure is quite correct. As an examination of specimens in alcohol proves, 

 the groove is present only on the upper side, merely shining through beneath, 

 the under surface of the clipeus being covered by a thin membrane, which is 

 continuous with the membrane of the head. 



In a dorsal view (PI. XII.— XIV. figs. 1. 3. 5. 8. 10) the clipeus projects laterally 

 beyond the edge of the frons, there being here a gap between the clipeus and the 

 head which is filled up by the apical portion of the first segment of the antenna. 

 The hind edge of the clipeus is always crescent-shaped centrally, the curve being 

 sometimes stronger and sometimes flatter, and there is often a slight indentation 

 sit each side of the central portion of the arch. The sides of the hiud margin are 

 curved in the inverse sense, and always bear a number of bristles, which are 

 directed obliquely upwards, the most lateral of these bristles being the longest. 

 There is a double outline to the hind margin, owing to the clipens having a 

 certain thickness and the upper edge of the margin projecting farther backward 

 than the lower edge, so that the upper edge slightly overlaps the anterior margin 

 of the frons when the clipeus is bent upwards. On the under side we find, near 

 each antenna, a kind of hasp and angle connecting the clipeus with the head. 

 This consists, on the clipeus, of a more or less ribbed incrassation in fan-shape, 

 which narrows posteriorly, where it is raised and meets a corresponding elevation 



♦ Zool. Jalirliklt., Suppl. vii. p. 373. lali. 20 (1901); id. llec. Iiid. Miis. iii. p. 271 (I'.IO'.l). 



