EXYSMA. 145 



EXYSMA. 



Corpus orbiculare vel suborbiculare, parvum. Antennae 10- vel ll-articulatae ; clava triarticulata, hand elongata r 

 laxe articulafca ; articulis duobus basalibus validis, intermediis (sex) subquadratis, tertia haud elongata. 

 Pronotnm breve convexum, transversnm, lateribus tenuiter reflexis ; sulcis tenuibus, basi latius impressis. 

 Prosternum latum, lanceolatum, punctatum. Elytris pubescentibus, punctatis. Sutura {E. joarvulce) 

 stria leviter impressa, vel (E. Icevigatce &c.) estriata. Tarsi 4-articulati, filiformes. Palporum labialium 

 articulis duobus ultimis latis trapeziformibus, maxillarium articulo ultimo subulato, apice subtruncato. 



Exysma is apparently very near to Mycetcea and Symbiotes. I have described as 

 belonging to the latter genus two very small species from Japan, which have also very 

 close relationship with the small insects for which I now propose this new name. It 

 would be difficult to assert in what essential particular these insects differ from 

 Symbiotes ; but it would be equally unsatisfactory to place them in that genus. The 

 form is orbiculate, the antennae much stouter, the thorax quite different in shape. I 

 think it likely that the Japanese species alluded to may pertain to the genus, and that 

 Microxenus, Wollaston, from the Cape of Good Hope, is a close ally. 



Exysma is easily distinguished from Dialexia by the thorax having basal sulci, and 

 by the superior number of joints in the antennae. 



A. Antennae eleven-jointed. 



1. Exysma parvula. 



Breviter oblongo-ovalis, saturate ferruginea; elytris crebre distincte punctatis, stria suturali distincta, mar- 

 ginibus subexplanatis, parcius pilosis. Long. 1|-1| millim. 



Hab. Guatemala, Capetillo (Champion). 



Suborbiculate ovate. Antennae short and rather stout, about as long as the thorax 

 and head together ; rusty-red, rather paler at the base and apex. Thorax transverse, 

 narrower in front, convex, the sides a good deal rounded, the front and hind angles 

 acute; the sulci deep and wide at the basal margin, plicate externally, continued as 

 fine impressed lines to the front margin. The elytra are as wide as long ; the widened 

 margin is separated from the convex discoidal part by a rather evident sulcus, which 

 commences outside the small humeral callus ; upon the margin itself is a row of 

 obsolete but larger punctures. 



B. Antennae ten-jointed. 



2. Exysma laevigata. 



Breviter rotundata, fere hemisphserica, ferruginea, parce pubescens, antennis pedibusque dilutioribus, prothorace 

 minutissime punctulato, elytris lsevigatis, stria suturali nulla. Long, vix ultra 1 millim. 



Hab. Mexico, Toxpam (Salle), Teapa in Tabasco (H. H. Smith). 



This little insect is allied to E. parvula, and is about the size of the smallest 

 specimens of that species, but is more convex. The antennae are of a clear ferruginous 

 colour ; the club is more compact than in that species, and the length of it is equal 



biol. cente.-amee., Coleopt., Vol. VII., February 1891. U* 



