EM'BIO'PTERA OF THE NEW WOELD — ROSS 477 



Although the species are identified most readily by comparing 

 figures and by using distributional data, the following key may be of 

 additional value : 



KEY TO SPECIES OF DILOBOCERCA (MALES) " 



1. Left cercus-basipodite (LCB) with ventral lobe short, shorter tlian dorsal 



lobe; fleshy or broadly iwinted !*■ 



LCB with ventral lobe longer than dorsal lobe ; fingerlike or acutely 

 pointed 10 



2. LCB with dorsal lobe tapered to a sharp point, uuclef t ; British Guiana-; 



intrieariia^ 

 LCB with dorsal lobe bearing a pair of distal "claws" g 



3. LCB with ventral lobe fleshy, membranous, rounded ; Tres Marias Islands^ 



Mexico pacilica 



LCB with ventral lobe sclerotized (at least veutrally), broadly pointed— 4 



4. Left tergal process (10 LP) with outer margin deeply notched just behind 



apex; basal segment of right cercus strongly, acutely lobed inward at 



apex; Oaxaca, Mexico emarginata 



10 LP with outer margin straight, not notched ; basal segment of right cercus 

 only obtusely rounded distad, if at all lobed 5 



5. Northern South America g 



Guatemala northward 7 



6. Head narrow, parallel-sided; eyes small, scarcely inflated; submentum as- 



long as broad, sides strongly arcuate ; color black ; Venezuela nigrina 



Head with sides rather strongly convergent; eyes large, strongly inflated; 

 submentum longer than broad, sides weakly arcuate; color brown; 

 Venezuela gig:antea 



7. Basal foramen of right cercus with ventral margin obtusely angulate; 



Guatemala excisa 



Basal foramen of right cercus with ventral margin acutely angulate 8 



8. Eyes small, scarcely inflated, interspace more than two eye widths wide; 



Brownsville, Tex lobata 



Eyes large, strongly inflated, interspace only one eye width wide 9 



9. 10 LP with apical margin of outer portion bi-emai ginated, acutely pointed 



medially; Veracruz, Mexico jalapae 



10 LP not as above; Chiapas, Mexico chiapae 



10. Ventral lobe of LCB fingerlike in form, rounded distally ; southern 



Brazu plaumanni 



Ventral lobe of LCB narrowly conical in form, sharply pointed distally 11 



11. Right mandible with a medial tooth on inner margin ; southeastern United 



States vandykei 



Right mandible without such a tooth ; Cuba caribbeana 



OLIGEMBIA (DILOBOCERCA) LOBATA, new species 



Figures 127-129 



Male (in alcohol).— Sclerites smoky brown, intersclerotal mem- 

 branes pale tan. Head and antennae black; mandibles amber yellow. 



"0. oUffotomoides (Enderlein) is not included, as, in the lieht of present knowledge 

 It is unrecognizable. 



