312 
COSTA RICAN DERMAPTERA AND ORTHOPTERA 
RHYACOLABIS new geiiusi 
This interesting genus shares certain features with Neoloh- 
ophora and others with Neocosmiella, to lioth of which it is 
ridatcd. P^'roni these two genera, however, it differs in the 
surface of the alaloinen ])eing hirsute, the tegininal keel complete 
and the pronotum weakly transverse. From Neolobophora, 
Rhyacolahis also can lie distinguished by the tegminal keel Ix'ing 
strongly developed, carinately elevated, instead of moderati'ly 
('vident and not carinately elevated, while it agrees with Neolo- 
hophora in having the surface of the tegmina minutely shagreen- 
ous when seen under a strong lens, and apparently smooth to 
the naked eye. From N eocosmiella the new genus readily can 
be distinguished by the tegmina having their surface as above, 
and not coarsely coriaceo-punctate, as well as in the lateral 
portions of the pronotum being broad and gr'’at]y encrouching 
upon the disk mesad, instead of narrow and subeepud, as in 
NeocosmieUn. 
In the absence of the male sex of Rhyacolahis it may siHun 
hazardous to describe the insect as a new genus, l)ut as the s])ecies 
on which it is founded has bi'en figured and rejiorted for many 
yi'ju's, and th(‘ diffei-imcc's ajipear, from our knowledge of allied 
g(‘ii(M'a, to b(‘ of considi'rabh' im])ortance, no other course is 
o])(m. This is clearly evident when it is realized t hat to af tmupt. 
to fit it in ('itlu'r of the otlu'r genei'a would do violenci' to their 
coh('siv(mess. 
Liiu'ai’ly arranged the genera of this as.smnblage, which we 
hav(‘ luul to ('xaniine in connection with our ('osta Fican study, 
would stand as follows; Rhyacolahis, N^eocosotiella, Neolohophora 
and Melresura. The gmius Rhyacolahis has a facies which is 
appri'ciably Ancistrogastrine. The African genus Archidax 
bun-'® is a])parently a near i-(dative of Rhyacolahis, having a 
compk'to hunu'ral ti'gminal ki'cl, but it has the abdonuMi smooth 
and lh(' limbs ('longatc', whik' doubt k'ss ollu'i’ inpioi'taid featui'i's' 
would b(‘ I'ound to ('xist on comjiarison. Archidax has a ])rono- 
liim and lind) (k'velopinent much as in Ncolohojdiora and Xco- 
co.saiiclla, wliik' its g(‘n('raJ l:ici('s suggi'sts Mefresara, but I In' 
h('ad s( nicl mo aloiu' ])r('venls conlusion with th(“ lalt('r genus. 
l''r(iiii p’jy.- ritlanio, and farce jik. 
'"Atin. and Mag. .\;d , llisl., (S), i\-, p, 121, (lilO'.l). 
