TRIQUETRA. 33 
remarks, “A precedente [i.e. 7. virescens] vix differt”; TZ. grossa and T. virgata, how- 
ever, are more closely allied in general appearance to one another than to 7. virescens, 
which appears to be a smaller form of the male with the humeral horns rather shorter 
and less slender. Among specimens in our collection from Irazu there are males just 
like Signoret’s typical specimen of 7’. virescens referred to by Fairmaire (which I have 
before me), and females exactly like his 7. grossa. On comparing a large series it is 
evident that there is considerable variation in the length and direction and the 
straightness or slight recurvation of both the dorsal and humeral horns, and that it 
would be very easy to describe fresh species if it were not for intermediate forms 
leading from one to the other. In the Vienna Museum collection there are only five 
specimens belonging to these three so-called species, four females and one male—the 
male being placed under 7. virescens, two females (which differ considerably inter 
se) under 7. virgata, and two females under T. grossa. On comparing them, however, 
with the series in our collection it is obvious that they must all be referred to one 
species. A specimen from Panajachel is figured. 
2. Triquetra veruta, sp.n. (Tab. III. figg. 9, 9a.) 
Minor, fusco-brunnea ; pronoto longo, angustiori, fortiter punctato, rugoso, humeris modice prominentibus, 
haud porrectis, nigris ; cornu dorsali elongato, fere recto, acuto, lateribus ab humeris angustatis, in pro- 
cessum apicalem longum productis; tegminibus brunneis, venis dilutioribus, margine externo apicem 
versus hyalino ; pedibus abdomineque brunneis vel fusco-brunneis. 
A comparatively small and narrow species, of a dark brown colour, with the pronotum very coarsely and 
rugosely punctured in irregular rows; humeral prominences moderately long, at right angles to the pro- 
notum, and not extended forward; dorsal horn long and sharp, almost straight, but very slightly recurved 
at the apex, ribbed at the sides; dorsal raised line continued from above the head to the tip of the horn, 
and thence to the apex of the pronotum, which is long and extends considerably beyond the abdomen, 
but not to the apex of the tegmina; tegmina and legs brown, the former with the veins lighter. 
Long. 9, cum tegm. 10 millim.; lat. inter cornua 6 millim. 
Hab. Panama (Boucard, in Mus. Holm.). 
I found a male specimen of this distinct little species among some undetermined 
Homoptera sent me for examination by Dr. Aurivillius; it is allied to Umbonia obscura, 
Walk., but differs entirely in the shape of the humeral horns of the pronotum. 
8. Triquetra apicalis. (Tab. III. figg. 11, 11 a.) 
Umbonia apicalis, Walk. List of Homopt. Ins. ii. p. 518°. 
Hab. Panama, Bugaba (Champion).—Co.omBIA 1. 
This species may easily be distinguished from the preceding by the formation of the 
humeral and dorsal horns, which are long and acute, and extended forward in front of 
the head, so that, if viewed sideways, their tips are almost on a level, that of the 
dorsal horn projecting rather further forward than the other. It is also allied to 
Triquetra (Umbonia) turrita, Fairm.; but that insect, which inhabits Brazil, is rather 
BIOL. CENTR.-AMER., Rhynch. Homop., Vol. II., October 1894. *5 
