1921] NATURAL SCIENCES OF PHILADELPHIA. 213 



The present specimen is apparently somewhat larger than the 

 individual originally described; length of body 17, length of prono- 

 tum 4.6, width of pronotum 6.7, length of tegmen 16, width of teg- 

 men 5.6 mm. 



The genus Trihonidium includes species with pronotum impresso- 

 punctate and cephalic margin convex, as in Zetobora. The prono- 

 tum is, however, not broadly though conspicuouslj^-eflexed toward 

 the cephalic margin, agreeing in this respect with Phortioeca instead. 

 The species are of small size compared with those of the allied genera 

 and in the present species the pronotal magnitude is comparatively 

 very small. 



Tribonidium amplum new species. Plate XI], flgiires 9 and 10. 



This insect is evidently closelj^ related to T . transversum (Brun- 

 ner)," differing in the larger size, more ample pronotum and tegmina 

 and. wings, which in the male sex, show no reduction whatever. 



Compared with the male of T. signaiicollis (Burmeister) recorded 

 above, the present males are seen to differ in the conspicuously 

 broader pronotum, with impressed punctae smaller and nearlj^ ab- 

 sent in the cucullate portion, scattered and minute caudad of that 

 area, entire cucullate and discal portions of pronotum appreciably 

 flattened and more ample organs of flight. 



Type: cf ; Tijuca, Rio de Janeiro, Brazil. [Paris Museum.] 



Size large, form moderately broad, for this genus of small and 

 moderately broad, though graceful, species. Head flat, interocular 

 space broad, shghtly over half as broad as that between the antennal 

 sockets, interocellar area shallowly concave; ocelli large, their sur- 

 faces at a decidedlj^ obtuse angle to the interocellar area. Maxil- 

 lary palpi very short, third joint subequal in length to the enlarged 

 fifth joint, fourth joint three-fifths as long, expanding strongly dis- 

 tad. Pronotum ample; cephalic margin broadly convex to the 

 rounded lateral angles, weakly reflexed in lateral portions; lateral 

 angles situated slightly caudad of median point, latero-caudal mar- 

 gins to shoulders of equal obliquity and convexity to lateral portions 

 of cephalic margin, caudal margin between humeral shoulders trans- 

 verse, with median angulation feebly suggested Pronotum cucul- 

 late above head, this and the area caudad to the shoulders raised 



" It appears doubtful from the literature that Saussure's assignment of trans- 

 versum under his monaslicum is correct. From his description and figure of the 

 latter species it would appear to differ from transversum in having a pale trans- 

 verse band on the vertex, the pronotum more ample (5.5 by 8.5 mm.), with caudal 

 margin more strongly transverse, but with tegminal and wing length apparently 

 proportionate. Unfortunately Saussure did not give separate measurements 

 for the sexes. A smaller Brazilian female recorded by that author, having the 

 head dark and immaculate is apparent!}' referable to transversum. 



