214 CLA.VICORNIA. [Meh'get//es. 



with interstices smootli, or at most showing' very 

 faint traces of cross striatiou; forehead with an- 

 terior margin straight; colour black or leaden 

 bhxck. 



A. Anterior tarsi of male strongly dihatod ; thorax 

 only a quarter broader than long, at least as 



broad as elytra M. flatipes, Sturm. 



B. Anterior tarsi of male not or very sliglitly 

 dilated ; thorax twice as broad as long, narrower 



than the base of elytra M. picipes, Sturm. 



2. Tliorax and elytra with fine but very distinct cross 

 reticulation between punctures; foi'ehead with an- 

 terior margin emarginate ; colour leaden black . . M. rotundicollis, Bris. 



3. Thorax quite smooth between punctures ; elytra 

 with line, though distinct, cross reticulation ; tore- 

 head with anterior margin sti'aight ; body with 



strong purple metallic reflection . M. STMPnYri, Heer. 



iv. Anterior tibia; serrate or pectinate for at least two- 

 thirds from apex ; teeth often irregular, but always 

 distinct and more or less strong. 



1. Upper surface very scantily pubescent, entirely 

 smooth between punctures ; legs lighter or darker 



brown ; anterior tibias serrate. 



A. Anterior tibiaj dilated from above middle ; 



thorax nearly as long as broad M. NANUS, Er. 



B. Anterior tibia! not dilated from above middle ; 



thorax short, much broader than long . . . , M. seruipes, Oi/U. 



2. Upper surface very thiclvly pubescent, thorax and 

 elytra smooth between punctures, scutellum only 

 with strong cross striatiou ; legs black ; anterior 



tibia) more or less pectinate M. murinus, Er. 



v. Anterior tibia3 very finely toothed, but with tw^o or 

 three distinct, though small, outstanding teeth, 

 situated at some distance from one another, and 



separated by two or more smaller teeth. 



1. Upper surface shining black, with slight traces of 

 cross striatiou between pvinctures ; anterior tibiae 

 with two outstanding teeth ; legs black, anterior 



tibiffi pitchy M. LUGTTBKis, Sturm. 



2. Upper surface dull black, with plain cross reticula- 

 tion ; anterior tibiaj with two outstanding teeth ; 



legs dark, anterior pair dark red. 



A. Forehead straight ; anterior tarsi of male very 



strongly dilated M. OBSCURUS, Er. 



B. Forehead emarginate; anterior tarsi of male 



not strongly dilated. 

 a. Male with a small transverse keel on the last 



abdominal segment M. ERTTHROPUS, Oi/Il. 



h. Male with a very strong transverse keel on 

 the last abdominal segment, divided by a 

 broad semicircular excision into two divisions, 



each ending in a strong sharp tooth . . . . M, bidentatus, Bris. 

 S. Upper surface shining black, with very slight 

 traces of cross striatiou ; anterior tibiaa with three 

 short outstanding teeth, separated from one another 

 by one or two smaller teeth ; logs dark, anterior 

 tibire occasionally lighter M, exilis, Sturm. 



