190S] FROST — ATTELABUS RHOIS AND PARASITE 31 



Sexual Characters. 



Male. — Apical angles of the beak prolonged, acute; beak longer before the eyes 

 and slenderer than in the female causing the eyes to appear slightly more prominent. 

 By careful comparison the antennae will be found to be stouter, with the club larger 

 and the joints more loosely articulated than in the female. Head narrower behind 

 the eyes than the female, with a prominent median carina extending from the posterior 

 line of the eyes to the occiput, carina often black and sometimes with a black area 

 surrounding it. Prothorax more narrowed in front than in the female. Anterior 

 tibiae arcuately curved, slender, equal in length to one and one half times the length 

 of the prothorax; all the tibiae are armed at the distal end with a single curved hook, 

 the inner or posterior one wanting; all tibiae with two rows of serrations on the inner 

 edge. The anterior femora, viewed laterally, are straight on the upper edge — that 

 is, the clavate portion is asymmetrical; the femora are longer and the coxae longer 

 and stronger than in the female. The prosternum is not so deeply excavate (or emar- 

 ginate) in front, and with an evident depression before the coxae. 



Female. — Apical angles of the beak only very rarely prolonged; beak shorter 

 and stouter, broader and thicker at the apex than in the male. Head with the carina 

 usually replaced by a smooth median line, sometimes with a black area as in the male. 

 Prothorax broader in front. Anterior tibiae equal to or slightly exceeding the length 

 of the prothorax; the inner row of serrations on the inner edge of the tibiae are more 

 prominent than in the male ; first serration sometimes half the length of the inner hook 

 of the tibia. In the females all the tibiae are armed at the distal ends with two hooks 

 curving inward toward the body, the outer one of which is longer and stouter. All 

 the femora are symmetrically clavate. Prosternum emarginate or excavated in 

 front nearly to the coxae. 



I am indebted to Mr. Frederick Blanchard for pointing out the characters of the 

 prosternum, and antennae, and for informing me that the serrations of the tibiae are 

 disposed in two rows. He has also very kindly verified the other characters from 

 specimens in his cabinet. 



My few specimens of Aitelahus analis and hipuMidafus agree Vv^th rhois in the 

 sexual difference of the tibial hooks, and Mr. Blanchard writes me that his specimens 

 of analis, nigripes, and bipustulatus all differ in the same manner sexually. He also 

 says regarding the two last mentioned species, "It seems not to have been noticed 

 that in AUelahus nigripes and bipustulatus the beak is obliquely truncate beneath and 

 that the gular peduncle is obliquely compressed each side, converging to a distinct 



