72 HEMIPTERA-HOMOPTERA. 
MYSIDIA. 
Mysidia, Westwood, Trans. Linn. Soc. xix. p. 7 (1842). 
Derbe, Fabricius, Syst. Rhyng. p. 81 (ad partem). 
This genus, as far as structure is concerned, is closely allied to Derbe, under which it 
is included by the older authors; the swollen second joint of the antenne is, however, 
as a rule, more pointed and less truncate. In general appearance these insects are very 
different from the members of the last-mentioned genus, having the veins much less 
marked and being for the most part of a white and more or less opaque colour; the 
apical areas of the tegmina, moreover, are wider and fewer in number. Several of 
the species closely resemble certain small white Geometrid moths. 
Mr. E. A. Austen, of the British Museum, who has taken a considerable number of 
specimens of a small species of this genus in the Amazons region, informs me that they 
run very swiftly on the upper surface of leaves, with their wings partially raised. 
1. Mysidia albipennis. 
Mysidia albipennis, Westw. Trans. Linn. Soc. xix. p. 7, t. 1. fig. 3’. 
Hab. Mexico, Vera Cruz!; Honpuras (Mus. Brit.). 
I cannot satisfactorily identify this insect with any species in our collection. 
2. Mysidia acidalioides, sp.n. (Tab. VIII. figg. 17, 17 a.) 
Albida, unicolor; capite ante oculos magnos vix producto, excavato ; pronoto perangusto; tegminibus amplis, 
sat latis, alis quoque amplioribus quam quod in hoc genere usitatum est ; corpore pedibusque testaceis. 
A rather large white species, unicolorous, except for a minute spot on the costal margin and two others on the 
interior margin of the tegmina; head scarcely produced beyond the large eyes ; pronotum very narrow ; 
tegmina and wings broader and ampler than is usual in this genus; venation distinctly but not strongly 
marked; legs and body testaceous ; legs very slender, with the small apical spines of the tibis more 
marked than in some of the allied species. 
Long. 15 millim.; lat. ad hum. 3 millim.; exp. tegm. 28 millim. 
Hab. Panama, Bugaba, Volcan de Chiriqui (Champion). 
3. Mysidia costata. (Tab. VIII. figg. 18, 18a.) . 
Derbe costata, Fabr. Syst. Rhyng. p. 81°. 
Derbe squamigera, Fabr. loc. cit. p. 81’. 
Mysidia costalis, Walk. List of Homopt. Ins. ii. p. 398°. 
Hab. Guatemata, San Isidro (Champion); Panama, Bugaba (Champion).—AMAzons, 
Para >. 
Au example from Bugaba is figured. 
