DYNASTIN.E 115 



less apically, the suture extremely fine and feeble; prothorax rather 

 more than twice as wide as the medial length, the sides broadly 

 rounded, gradually very moderately converging before the middle, 

 the apex broadly, deeply sinuate, the prominent angles well defined, 

 the basal obtuse and rounded; marginal bead thick and strong, 

 flatter but entire at apex, minutely angulate at the middle, wholly 

 obsolete throughout the basal margin; punctures rather large, 

 sparsely and subevenly disposed throughout; scutellum ogival, 

 minutely and remotely punctulate; elytra but little longer than wide, 

 barely wider than the prothorax, slightly inflated except basally, 

 rapidly and very obtusely rounded at apex, the surface with very 

 coarse and somewhat irregular, broadly and rather deeply impressed 

 sulci, each with a well spaced series of rather small shallow punctures 

 along the bottom; pygidium transverse, moderately convex, with 

 rather coarse shallow circular and close-set punctures basally, each 

 bearing a short, centrally placed hair, the punctures gradually 

 finer and sparse apically but with similar short stiff hairs; middle 

 coxa3 narrowly separated ; legs slender, the tarsi ( 9 ) slender and 

 filiform; abdominal segments subequal, each with a transverse series 

 of rather large shallow annular punctures, bearing very small hairs, 

 the punctures obsolete medially. Length (9) 21.5 mm.; width 

 12.0 mm. Isthmus of Panama (Culebra Cut), Gaillard. [ Cyclo- 

 cephala carbonaria Arrow] *carbonaria Arrow 



The lateral edges of the elytra are only very feebly thickened 

 and a little more arcuate at the middle in the female. 



Stigmalia n. gen. 



This is a large genus, wholly neotropical and above the average 

 in point of corporeal size, including in fact the largest species of 

 the tribe. It comprises several types of coloration and pronotal 

 structure but otherwise is homogeneous, and it appears to be a 

 genus in a true sense of the word. The ornamentation types are 

 represented by mafaffa, lucida, gregaria and atricapilla, as denned 

 below, but a surprising and unexpected structural character sharply 

 divides the mafaffa section into two groups, having ornamentation 

 so absolutely similar that on first glance they would be unhesi- 

 tatingly placed together as a single species; in one of these groups, 

 mafaffa proper, the base of the pronotum is completely immarginate, 

 as is the general rule in Stigmalia, while in the other, represented 

 wholly by apparently undescribed species, there is an entire basal 

 bead, as thick and conspicuous as in the genus Augoderia, showing 

 more clearly than in any other instance known to me, the lack of 

 taxonomic value possessed by the modification of the posterior 



