372 Trans. Acad. Sci. of St. Louis. 



coxae more widely separated than usual. Palaearctic and Nearctlc Atlan- 

 tic regions Leptolinns 



The two following genera are attached provisionally to the 

 Xantholini. They are founded upon the original and wholly 

 inadequate descriptions of Le Conte and consequentlymay be 

 greatly out of place. My only excuse for publishing them at 

 this time is because their type species cannot be assigned satis- 

 factorily to any of the other genera thus far proposed : — 



Body very minute, tlie palpi, antennae and front tarsi as in Leptolinus; head 

 rather convex, the base truncate with the angles narrowly rounded; 

 punctures of the head and pronotum small in size, sparsely scattered; 

 middle coxae not examined. Nearctic Atlantic regions. \^= Leptolinus 

 Lee. nee Kr.] ...MicrolinuB 



Body minute, subcylindric; head convex, narrowed in front, the base trun- 

 cate, the surface distinctly but not densely punctate toward the sides; 

 antennae somewhat longer than the head, with the outer joints gradu- 

 ally much thickened; maxillary palpi with the fourth joint very small, 

 acicular; middle coxae contiguous; front tarsi not dilated; prothorax 

 distinctly though not densely punctured, with a broad smooth dorsal 

 line; sutural "stria" of the elytra obsolete. Florida. \^ = Metoponcus 

 Lee. nee Kr.] Oligolinns 



It will be noted that the genera of the above table from 

 DinoUuus to Xanfhohypnus, have the prouotum smooth and 

 wholly devoid of the dorsal series of punctures, that those 

 from Nudohius to Leptacinodes have some sparse dorsal 

 punctures arranged for the greater part in a few more or less 

 irregular series, and those from Stictolinus to Leptolinus have 

 the pronotal punctures confused throughout the surface, ex- 

 cept along a rather wide smooth median line and more close- 

 set as a rule, except in the South African JSfotoliniis and No- 

 tolinopsis. The significance of this pronotal sculpture is 

 shown in many ways, as for example in the mandibles, those 

 genera without dorsal punctures having the mandibles convex 

 and unmodified externally, while those with dorsal punctu- 

 ation, embracing all the other genera of the table, have them 

 deeply grooved. The importance of this mandibular char- 

 acter, which is thus correlated with the absence of dorsal 

 punctuation, will be recognized at once. The foreign genera 

 indicated by asterisks in the table may be referred to as 

 follows : — 



