132 NORTHERN ZOOLOGY. 



M. Latreille, in his last work, 5 has united to this genus Amphimalla solstitialis, which on 

 account of its having only nine joints in its antenna?, he had, and I think with reason, considered as 

 distinct ; for besides this character, the mandibles are of a very different shape, being shorter and 

 smaller in proportion to the size of the animal, with the truncated portion narrower and concavo- 

 convex ; the maxilla; are armed with only four teeth, and are more incrassated at the base ; the claws 

 have only a minute tooth at the base, and the elytra are many-ridged, besides other minor differ- 

 ences ; I think, therefore, I am justified in still considering them as belonging to different genera. 

 Rhizotrogus should be placed between Amphimalla and Melolontha, from which last it may always 

 be distinguished by having only three leaves in the knob of its antenna;. 



As Latreille's character of the genus is insufficient, I have drawn up a new one. 



(180) 1. Rhizotrogus fervens. Fervid Rhizotrogus. 



Melolontha fervens. Gyll. Schon. Si/n.in, App. 74, 106 



ferivida. Oliv. Ins. i, 5, 24, 21, t. ix, / 109? 



quercina. Knoch. Ins. i, 74, 2? 



Length of the body 9i — 10 lines. 



Two specimens taken in Lat. 54°. B, in Canada by Dr. Bigsby. 



DESCRIPTION 



Body either pale or dark chestnut, rather glossy, naked. Head short, black, thickly and grossly 

 punctured, vertex transversely impunctured ; nose separated by a bisinuated line from the front, 

 anteriorly reflexed and subemarginate ; antennae testaceous with the knob in the males paler and 

 elongated : prothorax transverse, usually darker in the disk, punctured with scattered punctures ; 

 sides subobtusangular with the margin very obsoletely notched ; behind subrepand or bisinuate : 

 scutellum with a few scattered punctures towards the sides : elytra four times the length of the 

 prothorax, with three obsolete ridges, very slightly punctured and wrinkled : disk of the abdomen 

 impunctured: breast covered with long hairs : legs testaceous; cubit obtusely tridentate ; tarsi longer 

 than the tibia;. 



Variety B. Rather wider in proportion, entirely dark chestnut, the legs excepted. In every 

 other respect precisely the same. 



5 Crust. Arachn. et Ins. i, 561, note 1. 



