EUPLECTINI 117 



Key to the Subgenera 



Tenth (penultimate) antennal segment transversely triangular and 

 bilaterally asymmetrical (approaching Dalmosella and Melba- 



mima) known from Brazil and possibly Argentina 



ASYMMELBA, new subgenus 



Tenth antennal segment transverse, lenticular or practically bilater- 

 ally symmetrical 2 



2. Vertex with four free foveae arranged in an anterior pair near anten- 



nal bases and a posterior pair between the eyes; no vertexal sulci 

 connecting the foveae (approaching Ramelhida) known from 



Antilles RAMELOIDEA, new subgenus 



Vertex with a pair of vertexal foveae between the eyes, these foveae 

 more or less connected by an arcuate vertexal sulcus 3 



3. Vertex with a large, deep, transverse excavation between the eyes, 



this depression medianly tuberculate; known from French Guiana 



VERTELBA, new subgenus 



Vertex simply convex or flattened between the eyes 4 



4. Head quadrate in outline, and in the males (seven sternites) anter- 



iorly dilated; known from the Antilles (Raffray, Group IV) 



QUADRELBA, new subgenus 



Head narrowing anteriorly of the eyes 5 



5. Front prolonged anteriorly above the epistomal area, this extension 



more pronounced in the males (seven sternites) than in females (six 

 sternites), but distinct in both sexes; known from the Antilles and 



possible Guatemala (Raffray, Group III) 



FRONTELBA, new subgenus 



Front normally subtruncate to gently arcuate between bases of anten- 

 nae; includes all North American species and the Antilles (Raffray, 

 Group II, and original Melba of Casey) MELBA, s.s. 



Key to Asymmelba 



Front transversely sulcate; tenth antennal segment strongly dilated 

 on mesial face and very asymmetrical; eleventh antennal segment 



conical clavata 



(0.9 mm.; Sao Paulo, Brazil) 



Front rectilinear, and with two deep transverse sulci; tenth antennal 



segment slightly asymmetrical; eleventh antennal segment ovate 



impressifrons 



(0.9 mm.; Sao Paulo, Brazil) 

 Melba impressifrons has aflBnities with both caviceps and temporalis. 

 Melba longicollis (Raffray, 1912), from Argentina may also belong in this 

 group, but the tenth antennomere is described as merely large and transverse. 



