EUPLECTINI 67 



8(7). Pronotura with a small, subspherical to subcylindrical anterior 

 lobe, and a very large posterior lobe, the small anterior lobe 

 acting as a bearing for the equally small pedunculate neck 



(PI. VIII, 7) RHEXIUS 



Pronotum without such a small anterior, pedunculate lobe. ... 9 

 9(8). Lateral pronotal margins unidentate, each side bearing a single 



tooth at middle of subbasal area 42 



Lateral pronotal margins pluridentate, each side bearing five 

 to six teeth (PI. VIII, 10) EURHEXIUS (in part) 



10 ( 6 ) . Base of each elytron with three foveae 11 



Base of each elytron with two foveae 21 



11 (10). Eyes invisible from above MITRACEPHALA 



Eyes visible from above 12 



12 (11). Disc of pronotum simple, with no trace of a fovea or a longi- 



tudinal median sulcus 13 



Disc of pronotum with either a median longitudinal sulcus, or 

 a central fovea or foveoid depression 15 



13 (12). Sternite IV very short, much shorter than II and III which are 



subequal in length LIOPLECTUS 



Sternites II, III and IV subequal in length, or gradually de- 

 creasing in length 14 



14 (13). Lateral pronotal margins entire; elytral base simply foveate, 



having a transverse basal carina ACTIUM (in part) 



Lateral pronotal margins with a small subbasal tooth, and 

 crenulate anterior to this tooth ; base of each elytron with a 

 multiarcuate, transverse, basal carina, the basal foveae be- 

 ing vestigial, and appearing as pits, one under each arc of 

 the transverse carina PANARAMECIA, new genus 



15 (12). Disc of pronotum with either a central fovea, or a foveoid 



depression 16 



Disc of pronotum with a long, median, longitudinal sulcus. ... 17 



16 (15). Ventral surface of head with a few stout, strongly capitate, 



rather spiniform setae; basal tergites with no basal carinae 

 on disc THESIASTES 



to-blunt ends; in several species the elevations are subdentate, minute and blunted denticles. 

 Thus a tooth may be distinct, but require high magnification to discern its form, this latter 

 condition is especially notable in the fifth group of Eurhexius with subdentate margins, as 

 contrasted with Aporhexius and Rhexinia with crenulate margins. 



In some cases there is a combination of these features. Thus Panaramecia has a basal 

 tooth, and anterior to this tooth the margin is minutely crenulate. Again in Fletcherexitis 

 the margin is subentire, with the area opposite the lateral pronotal fovea slightly granular 

 so that the line of the pronotal margin appears similar to our North American Rhexidius 

 in part. 



The above remarks refer to dry mounts on points. Microscope slides under high mag- 

 nification may show a crenulated margin to be composed of asperate tubercles, as in some 

 Thesium. 



