FEOM THE society's GARDENS. 679 



preantennal region being bent over on itself to form a longitu- 

 dinal channel, is a derivative of the other two species seems clear 

 from the observation made by Harrison that the larvae of 

 D. «s?/??^?neir^ca possess asyixi metrical heads of "a precisely similar 

 structure " to that found in the adults of tlie other two. 



A great deal more collecting and investigation are necessary 

 befoi'e any satisfactory conclusions can be di'awn upon the rela- 

 tionship of the Mallophaga parasites to their Sti'uthious hosts. 



Struthiolipeurus, gen. nov. 



Lipeuroid : antenna? sexually dimorphic. Incrassations of 

 anterior margin of head placed asymmetrically. Left mandible 

 with an enormous basal process almost as lai-ge as the mandible 

 itself. In the thorax clavicles present as thin splints running 

 inwards and backwards from the antero-lateral angles to join a. 

 band which goes vertically downwards to be inserted into the 

 ti'ansverse acetabular bar. Abdomen with thinly chitinised 

 transverse tergites. Two transverse rows of fairly long silky 

 hairs on each tergite. " Hairs at the sides numei'ous and fairly 

 long. Male copulatory apparatus characteristic. 



Genot^ype : Struthiolipeui'us asymmetricus Piaget (23, p. 54). 



The genus to include S. quadrimaculatus P. (3, p. 298). 



Struthiolipeurus asymmetricus P. ; (Text-fig. 25.) 



I collected several specimens of this (?pecies personally on a 

 live lihea in the Gardens. 



Male Cop'idatory Apparatus. — Basal plate: Dorsally trough- 

 shapeil, with a longitudinal median keel. At the posterior end 

 the sides of the trough become steep, and a bridge runs across 

 from side to side in the form of a fa.ir]y narrow transverse band, 

 from the middle third of which a parallel -sided plate runs forward 

 between the parameres, ending in a straight truncate margin, to 

 which the upper endomeres are attached. Beneath this transverse 

 band is anotlier running across the floor of the trough from side 

 to side. Like the dorsal one this sends forward a median piece 

 between the parameres, and near the end of it the penis arises. 

 'J'he posterior lateral angles of the basal plate ai'e much produced, 

 deep dorso-ventrally, and square. Parameres: long tapei-ing 

 rods, the apex curiously formed (see text-fig. 25, P). Mesosome : 

 Each upper endomere is roughly triangular, being broad at the 

 base and narrowing towards the tip, where it is slightly decurved. 

 The piece may best be likened to the rhamphotheca of some bird 

 of prey when macerated ofi' the skull ; it is actually double, 

 being bent upon itself, the two leaves gaping wide enough to 

 admit of the introduction of the dissecting-needle. In this way 

 each upper endomere " gapes " outwards. The lower endomeres 

 take origin further back, one on each side of the base of the 



