500 Mr. D. Sharp and Mr. F. Muir on the Comparative 



A less modified form is found in Xantholinus {Eulissus) 

 chahjhcvs (PI. LIII figs. 68, 68«) from Brazil ; in which the distal 

 end of the median lobe is short and tubular, drawn out into a point 

 on the ventral side, the median foramen being situate in the ventral 

 chitinous sclerite at the base of the short tubular distal end. 



X. phoenicopterus is also less modified than X. glabratiis, the 

 lateral lobe being much larger and the median foramen on the 

 ventral sclerite. 



Paedcrus o-i2)arius (PI. LIII figs. 69, Oda). 



The median lobe broad, slightly flattened and slightly bulbous 

 at base, the dorsal distal margin projecting beyond the ventral, 

 the median orifice being on ventral face beneath this projection ; the 

 median foramen small, near base slightly dorsal. The lateral lobes 

 broad, flattened, with curved pointed apices projecting beyond end 

 of median lobe, closely applied to sides of it, and attached to it near 

 the ventral edge of median foramen. Internal sac with large 

 curved spine (a) at base. Apex of sac not examined. 



Lathrohium hrunnipes. 



The median lobe bulbous and membranous, except on the ventral 

 basal part which is chitinous ; median orifice at tip ; median foramen 

 small, about the middle. Lateral lobes consolidated into a single 

 body, broad at base and narrow at apex where there are two small 

 points ; a groove runs along the ventral side. They form the 

 strongest part of the aedeagus and are consolidated to the ventral 

 face of the median lobe from the edge of the median foramen to the 

 tip. Internal sac not examined. 



L. fulvipenne is of the SAme type as L. hrunnipes, but the left 

 lateral lobe appears to be absent and the right is large and projects 

 as a curved spine ; there is also a chitinous support on the dorsal 

 side of the median orifice. 



L. horeale. 



The same type as L. bnmnipes, the lateral lobes being consolidated 

 into a single piece, the tij) being pointed and turned down like a 

 small hook, the median ventral line being keeled, not grooved. 

 The dorsal margin of the median orifice is supported by a small 

 chitin plate and a strong chitin piece with two hooks at the end 

 projects from the basal part of the internal sac. On each side of 

 the internal sac, near the base, is a patch of chitinous flat scales, 

 prolonged into prongs on the basal edge. When the sac is evaginated 

 the two-hooked piece on the dorsal side of the base turns over and 



