436 PROCEEDINGS OF THE NATIONAL MUSEUM vol 



like crown of short spinules; tarsi relatively long, hindpair nearly as 

 long as their tibiae; basal segment of hindtarsus longer than following 

 two segments combined. 



This genus was erected by Horn to receive the single species 

 Platydema laevis Haldeman. His only criterion for its separation 

 from Platydema is in the structure of the mesosternum and its re- 

 lation to the prosternum, a diagnosis which in itself is quite adequate. 

 Bates (1873b) added to the generic description the facts that the 

 antennae are more or less serrate at their inner edges and that the 

 epipleura are entire. In addition, he described six species from South 

 America. Between 1877 and 1878, Chevrolat described seven South 

 American species which have subsequently been referred to Liodema. 

 Three of these were originally placed in the genus Platydema, three 

 in Scajyhidema, and only one in Liodema. Chexn^-olat himself trans- 

 ferred these species plus one species of Platydema, described by Laporte 

 and Brulle, to Liodema, casting two of his own species into synonymy 

 with two of Bates'. Champion (1886) placed four species described 

 by Che^Tolat, one by Laporte and Brulle, and one by Bates as syno- 

 nyms of other recognized forms, at the same time adding two new 

 species from Central America. Gebien (1906, p. 219), upon exami- 

 nation of the Fabrician types in Copenhagen, discovered that Myceto- 

 j)hagus maculatum Fabricius is actually a Liodema. In his 1940 check- 

 list, Gebien recognizes 12 species of Liodema in the v/orld fauna, 

 simamarizing our loiowledge of the genus to date. 



It is quite possible that a number of species described by older 

 authors in the genus Platydema will eventually be found to belong here. 

 In general habitus, there is a striking resemblance between the two 

 genera except for the peculiar development of the mesosternum in 

 Liodema, a character which is often obscured in the mounting proc- 

 ess, particularly in older collections. 



The distribution of Liodema is almost entirely Neotropical, with 

 only one species occurring north of the Rio Grande. Several of these 

 (e.g., L. ohy dense Bates) are widespread, occurring from Mexico, 

 throughout Central America, and well into Brazil. 



Liodema laeve (Haldeman) 



Plate 3 (Figs. 13, 14) 



Platydema laevis Haldeman, 1848, p. 101. 



Liodema laeve (Haldeman). — Horn, 1870, p. 385. — Champion, 1886, p. 205. 



Description. — Broadly oval, strongly convex, dark brown to 

 black, smooth, moderatel}'^ shining. Head reddish in front of eyes, 

 black posteriorly, surface minutely and rather densely punctulate; 

 eyes large, flattened dorsaUy; antennae, labrum, mouthparts and legs 





