1921] NATURAL SCIENCES OF PHILADELPHIA. 217 



Sainte Marie, lower Oyapock River, French Guiana, 1900, (F. 

 Geay; in nest of wasp, Polyhia pygmaea Fabricius), 1 cT, 4 juv., 

 topotypes, taken with type. 



It would appear that fifteen specimens in all were secured from 

 the same nest, eleven of them being adult males. 



Holocompsa nitidula (Fabricius) 



1781. B[la(ta] nitidula Fabricius, Spec. Ins., I, p. 345, [[9], Surinam.] 



Demerara, British Guiana, 1901, (R. J. Crew), 4 cf, 49, [He- 

 bard Cln.] 



St. Georges, Oyapock River, French Guiana, 1 cf . 



OXYHALOINAE. 



Chorisoneura lata Rehn. 



1916. Chorisoneura lata Rehn, Trans. And. Ent. Soc, XLII, p. 253, pi. XV, 

 figs. 28 to 30. [ cf ; Para, Brazil. ] 



Gourdonville, French Guiana, 1 9 . 



This specimen is more intensively colored than the type. In this 

 genus, which includes a multitude of species, often very closely re- 

 lated, we believe the present association to be correct, though it 

 is impossible to be certain without males from the same locality. 



In the male type of lata, the head coloration is destroyed, traces of 

 a paler band between the eyes and a pair of dark flecks alone being 

 discernible. In the female at hand the head coloration is apparent- 

 ly as it would be in the type, had its coloration been retained. 

 Head with occiput ochraceous-tawny, terminating in a straight 

 line between the eyes, upon which are situated two slightly im- 

 pressed dots of dark brown, below this is a band of buff which widens 

 slightly laterad, in that portion having a larger impressed dot of 

 dark brown on each side, below this band the face is pale ochraceous- 

 tawny. 



Compared with C. panamae Hebard, this cephalic marking is seen 

 to differ principally in having the more widely separated pair of 

 dots, the larger and the pale areas confined to a transverse band in- 

 stead of spreading ventrad over the face. 



Chorisoneura guianae new species. Plate XIV, figures 11 and 12. 



This species is closely related toC. lata Rehn, 3° differing in its 



^° Referred to the Pellucida Group by Hebard, Mem. Am. Ent. Soc, No. 4, p. 

 127, (1920). In addition to the species assigned to that group, C. poststriga 

 (Walker) also apparently belongs. From the description of that species it may 

 be distinguished from the present by the dark face and differently colored teg- 

 mina. 



