422 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iii 



Pronotum: Length usually not more than half of width; lateral 

 margins converging on anterior half or more, with not more than six 

 setigerous punctures suhmarginally; transverse impression absent to 

 well-developed and complete; posterior margin broadly and slightly 

 curved or subtruncated; angles more or less rounded. 



Scutellum: Distinctly longer than broad, triangular, apex narrowed 

 and less than half of membranal suture. 



Hemelytron: Corial areas well-defmed; membranal suture straight, 

 convex or sinuate, not prolonged laterally; costa usually sharp, ex- 

 planate and with no or very few setigerous punctures; membrane not 

 over two-fifths of hemelytral length, sometimes brachypterous. 



Propleuron: Moderately convex; convexities and depression rugose 

 and/or punctate or smooth and impunctate; prosternal carinae promi- 

 nent. 



Mesopleuron (fig. 96): Flattened, evaporatorium occupying half 

 or more of segment, lateral margin strongly oblique, reaching near 

 or into posterolateral angle; posterior margin entire; mesosternum 

 with prominent, distinct, median carina on basal half or more of 

 nearly all species. 



Metapleuron (figs. 96, 97): Flattened to uneven; evaporatorium oc- 

 cupying mesal two-thirds or three-fourths, lateral margin convex or 

 straight and oblique; peritreme reaching or surpassing middle of seg- 

 ment, apical modification expanded posteriorly as semicircular, quad- 

 rate or triangular, more or less shining lobe, osteole usually opening 

 posteriorly on peritreme. 



Legs: Moderately long, slender; anterior tibia (fig. 120) moderately 

 compressed, with four to seven long, slender to stout spines on dorsal 

 margin; middle and posterior tibiae terete, spines of latter (fig. 144) 

 subequally developed on all margins; tarsal II shortest, I shorter 

 than III. 



Sternites: Strongly convex, shining or alutaceous, mth or without 

 setigerous punctures or rugae; posterior margin of each segment more 

 or less finely and acutely crenulate. 



Type of genus. — Melanaethus elongatus Uhler (1876), monobasic. 

 When Signoret (1883) transferred elongatus Uhler and Cydnus elongatus 

 Herrick-Schaeffer to Geotomus, Uhler's name became a homonym for 

 which Signoret proposed the new name parvulus. Lobonotus Uhler 

 was described for the lone species anthracinus Uhler (1877); because 

 Uhler's use of this name was preoccupied by Milne-Edwards (1863, 

 p. 280) in Crustacea, Bergroth (1891) proposed Lobolophus to re- 

 place it. Lobolophus must take anthracinus Uhler for type by ob- 

 jective s3rnonymy. 



