38o The Ohio Naturalist. [Vol. VIII, No. 8, 



that they are quite different species, as pointed out by Meinert 

 in his magnificently illustrated paper on this genus. Rilev was 

 evidently led astray by the fact that the females of the two species 

 are very much alike and that they often live together. Even 

 the females are, however, readily distinguished by a glance at 

 the underside. In Rh. Rileyi the mesosternum is yellow, uni- 

 colorous; in Rh. tenuipes it is yellow with the anterior margin 

 and two backwardly diverging bands brownish black. By 

 comparing numerous specimens I have found that this color- 

 difference, although not mentioned by Meinert, is perfectly con- 

 stant. Moreover, the breadth of the mesonotum as compared 

 with its length is different in the two species. Riley also over- 

 looked the different structure of the male antennae. 



I quite agree with Heidemann that the genus Hymenohates 

 Uhl. (1894) is founded on the winged form of Rheumatobates 

 Bergr. (1892), Rh. Bergrothi Mein. (1895) from the island of Gren- 

 ada, being the apterous form of H. imitator Uhl. (1894) described 

 from the same island. What Uhler describes as the "long thick 

 coxa" of the hind legs is really the trochanter which in this 

 species is enormously incrassated, forming a much greater mass 

 than the coxa. 



As the previously known species of the genus are inadequately 

 described in several points J here append a key to the species. 

 Knowing the winged form of but one species, I refer below only 

 to the apterous forms. I have not seen the female of Rh. imitator 

 and possessing a single carded male I do not know if the yellow 

 mesosternum in this species is unicolorous or spotted. 



1 (6) Mesonotum with a median yellow spot. Connexivum bright yellow, 



sometimes more or less infuscated. Eyes not reaching the meso- 

 pleura. The three last c? antenna! joints inserted in the apex of 

 the preceding joint in the usual normal way, first joint with a 

 slender spine beneath near the middle, unarrned above, its upper 

 margin straight, third joint with the basal part more or less 

 strongly curved, the apical part straight with a shallow spongy 

 pit on the posterior side. Middle femora in the c? straight, un- 

 armed, fringed with long hairs on the inner side, tibiae also 

 fringed with hairs on the inner side. 



2 (3) Mesonotum much broader than long. Second c? antennal joint 



with a slender spine beneath near the base, third joint with a 

 strong triangular tooth at the basal end of the not dilated spongy 

 pit, the lower margin of the pit beset with stiff hairs, fourth jcint 

 much shorter than third, straight, unarmed. Middle coxae in 

 the J* not thicker than the hind coxae, trochantera many times 

 smaller than the hind trochantera, femora fringed with long hairs 

 oh the inner margin near the base and apex, the remaining part 

 glabrous, tibiae somewhat curved in the middle where they are 

 thickest, from the base to near the middle fringed on the inner 

 side with short curved hairs, then along a shorter space with 

 long hairs. Hind trochantera in the (^ excessively incrassated, 

 much broader and thicker than the coxae and femora, armed 

 with a stout spine on the upper side, longly and thickly piloie 

 on the inner side, femora incras.sated and curved with a strong 

 tooth on the upper side before the middle and a curved chitinous 

 process on the inner side behind tlie tootli, near the apex on the 



