3 8 ° 
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. Riley 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 Hymenobates 
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 I 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 q 1 antennal joints inserted in the apex of 
the preceding joint in the usual normal way, first joint with a 
slender spine beneath near the middle, unarmed 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 q 1 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 q 1 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 joint 
much shorter than third, straight, unarmed. Middle coxae in 
the q* not thicker than the hind coxae, trochantera many times 
smaller than the hind trochantera, femora fringed with long hairs 
on 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 q’ 1 excessively incrassated, 
much broader and thicker than the coxae and femora, armed 
with a stout spine on the upper side, longly and thickly pilose 
on the inner side, femora incrassated and curved with a strong 
tooth on the upper side before the middle and a curved chitinous 
process on the inner side behind the tooth, near the apex on the 
