British Spi'cii'S of Ua\i\)\a3. ](»7 



ill botli Jf. ruficoU'is ami heijdcni tlio thoracic striro are about 

 oiie-tliird the lengtii of the tlioiax ; of //. wchii'kei he say.n 

 that there is a scinicircuhxr jiit inside each stiia, while he 

 mentions that in //. schaumii, Schilsky, the stiioe are short 

 jiikI ilei'p. Kcittcr(i5) uses the j)resence or absence of a 

 transverse tleprcssion ot' the thorax between the striio as a 

 systematic character, //. rnjicullis haviiif^ no such depression, 

 while its varieties — multipunctatus and hei/deni — have it, i\\ii 

 former variety beinf^ distinguished from the latter by having 

 the strity straight instead of curved. lie speaks of II. wehnc/cei 

 as having an interstrial depression. Ganglbaucr (7) also 

 lays some stress upon these ciiaracters, desciibing them in 

 each si)ecies and variety. 



1 have found the stria? of some use as an aid in determining 

 some of the species, but the presence or absence of a depres- 

 sion between them seems quite useless. In Jl. immacu/dtu'i 

 the striie are short and incurved, while in IJ. loehnckei, noma.r, 

 and aj>icuUs they are long and practically straight. In 

 Jf. rujicollis and heyJeni, liowever, althougli usually short 

 and abnost straigiit, they are sometimes distinctly incurved. 



On this character, therefore, it is often easy to confuse 

 //. ruJicoUis and immaculatus, on the one hand, and //. ritji- 

 coUis and icehnchei on the other. In //. flaviaiU'tH tiie striai 

 are usually very short, sometimes scarcely more than a rather 

 large puncture, but occasionally longer ones occur. 



The Characters of the Male. 

 1. llie Anterior Tarsi and Tarsal Claivn. 



Apparently Edwards was the first author to recognize any 

 differences in the claws of the anterior tarsi of certain species 

 of the group ; but he only mentioned them in the case of two 

 species, IJ. rujicollis and hei/deni. According to the cha- 

 racter of the chiws our species can be separated into two 

 groups — //. hej/deniy apicalis^ and nomax, having tiie pair 

 equal or subequal, and U. rujicollis, wehnckei, ami inimacu- 

 lalus, having them distinctly unequal. //. Jluviaiilis should 

 probably belong to the first group, but the difference between 

 the two is more noiicoable than in noma.v, for instance, 

 though much less than in rujicol/i-i. 



Tlie form of the claw-bearing segment is useful for distin- 

 guishing //. imniaculalns^ in which it is normally short and 

 rather thick, from loehnckei and rujicollis, in which it is 

 normally long and therefore thinner in appeal ance. 



If the claws are removed and (xaniined under high magni- 



