AMERICAN COLEOPTERA. 287 



NITIDULINI. 



Maxillse with a single lobe. Elytra nearly entire allowing at most 

 a portion of the pygidium to be exposed. Thorax at base not over- 

 lapping the elytra. 



These are in short the only characters separating this tribe from 

 the preceding. The genera composing it may be arranged in the 

 following manner : 



Prosternum depressed behind the coxse, not prolonged 2. 



Prosteriium elevated behind, often prolonged 6. 



2. — Tarsi very distinctly dilated on all the feet 3. 



Tarsi not dilated or very feebly so 4. 



3. — Antennal grooves strongly convergent. 



Labrum bilobed. Males with a sixth dorsal segment Epnraea. 



Labrum feebh'' emarginate. Males without sixth segment. ..Nitirtula. 



Antennal grooves parallel, passing directly backwards !§iteIi(Iota. 



4. — Mentuni broad covering the base of the maxillse Prometopia. 



Mentum not covering the maxillse 5. 



5. — Front not lobed over the antennae. 



Mandibles with tip slightly.bifid Phenolia. 



Mandibles not bifid at tip Omosita. 



Front lobed over the insertion of the antennee. 



Mandibles simple at tip, toothed posteriorly ..Soronia. 



6. — Mesosternum not carinate. 



Head without antennal grooves. 



Anterior tibiae not toothed externally Tbalycra. 



Anterior tibise bidentate at middle Perthalycra. 



Head with distinct antennal grooves. 



Tarsi not dilated. Body oval, pubescent Pocatlius. 



Front tarsi dilated. Body parallel and glabrous Orthopeplus. 



Mesosternum carinate. Tarsi all dilated ^leligetlies. 



In those genera in which the tarsi are said to be dilated, the asser- 

 tion applies to all the feet. In those with the tarsi not dilated it will 

 be observed that the males do sometimes have dilated front tarsi. 



On comparing this table with that given in the "Classification" 

 p. 83, several changes will be observed. Lohiopa has been changed 

 to Soronia the two genera not differing. Thalycra known also in 

 Europe has been added, following it two new genera, Orthopeplua and 

 Perthalycra are indicated. The latter genus was named but never 

 described by the late Mr. Gr. R. Crotch, and I adopt in full his names 

 as given in the ''Check List," the species having become generally 

 known under this designation. 



Very little can be said of the genera in the way of comparison 

 than is already made use of in the table. I was at one time led to 

 believe that the degree of development of the sexual segment might 



