TISIPHONE. URESSINOMA. 371 



Genus XV. ORESSINOMA. 



Oressina E. Doubleday MS. 



OcALis Boisduval MS. 



EuPTYcniA ? E. Doubl. List Lep. Brit. Mus. 



Body very small, slender, hairy ; wings large, triangular, with a broad central white bar ; hind ones beneath with 



deep fulvous snbmarginal lunules. 

 Head small, clothed witli loose hairs. 



Eyes prominent, naked. 



Antennw about two fifths of the length of the fore wings, very slender, composed of but very few joints, the 

 basal portion having the joints elongated, scarcely distinct, annulated with white ; the twelve terminal joints 

 much shorter, and forming a slender curved club finely carinated beneath. 



Labial Palpi slender, very compressed, very thickly hairy in front, the hairs set on at right angles, porrected 

 obliquely nearly to the level of the top of the eyes, and extending in front nearly as far as the length of the 

 head ; terminal joint very slender, acute, elongate-ovate, scarcely hairy. 

 Thorax small, oval, finely hairy. 



Fore Wings large, triangular. Fore margin slightly curved ; apical angle obtuse. Apical margin three fourths 

 of the length of the anterior, very slightly convex ; hinder angle rounded. Inner margin straight, nearly as 

 long as the apical one, but slightly clothed with scales. Median and postmedian veins very greatly swollen at 

 the base. Costal vein reaching the costa a little beyond the middle of tlie wing. Postcostal vein with its first 

 branch arising a little before the middle of the wing, before the extremity of the discoidal cell ; second branch 

 arising at about the same distance beyond the cell ; third and fourth branches arising at equal distances apart ; 

 the terminal part of the vein running into the rounded part of the tip ; the extremity of the upper discoidal 

 vein extending to the extremity of the convex portion of the tip. Upper disco-cellular vein extremely short, 

 transverse, arising at about half the length of the wing: middle disco-cellular much longer curved; the tij) 

 being directed outwards : lower disco-cellular rather longer, straight, oblique, terminating the discoidal cell 

 about the middle of the wing in almost a right angle, formed by its union with the basal part of the third 

 branch of the median vein, which is angulated at the place of junction, which is at a considerable distance 

 from its origin ; the space between the first and second branches of the median vein considerably elongated, 

 and equal in length to the space between the base of the wing and the first branch. 



Uind Wings large, subtriangular. Costal margin nearly straight, except at the base, where it is greatly elbowed, 

 so that the costal vein, which follows its outline, is much bent near its origin, but does not extend half the 

 length of the costa ; outer angle rounded. Outer margin with three rather deep scallops, fringed with hairs 

 rather than scales ; anal angle obtuse. Postcostal vein branching at a short distance from the base of tlic 

 wing, the branch extending to the outer angle. Upper disco-cellular vein arising at a very short distance 

 beyond the branch of the postcostal, curved obliquely : lower disco-cellular rather longer, straighter ; uniting 

 with the third branch of the median vein at a very short distance from its origin, closing the discoidal cell at 

 scarcely more than two fifths of the length of the wing in an acute point. First branch of the median vein 

 extending to the anal angle. The postmedian vein running into the anal margin, a little distance beyond the 

 extremity of the abdomen. 



Fore Legs of the male extremely small and delicate. The femur nearly equal in length to the tibia and tarsus 

 united; the two latter clothed with long very fine hairs. Tarsus small, destitute of joints and claws. Fore 

 Legs of the female much longer than in the male, very slender, scaly, with scarcely any hairs. Tarsus as long 

 as the tibia, much dilated at the tip where are several short spines indicating the joints. 



Four Hind Legs slender, scaly, scarcely hairy. Tibia and tarsi nearly destitute of short spines beneath ; tibial 

 spurs not distinct. Tai'sus rather longer than the tibia. Claws small, slender, very much curved, acute, 

 entire. Paronychia minute, bifid at the tip ; outer division very slender. 

 Abdomen elongate, slender, hairy. 



The type of this genus is a plain but delicate butterfly, a native of Colombia and New Grenada, remarkable for the very broad white 

 band across all the wings, which are but slightly clothed with scales ; the basal portion of the wing is pale brown, thickly marked with 

 minute darker transverse streaks, and the dark brown margin is elegantly varied beneath with a fulvous striga edged with white, [)arallcl 

 to the apical margin in the fore wings, but very strongly waved in the outer portion of the hind wings, botli wings being destitute of 

 ocelli, whence the specific name of the insect. Structurally this genus is distinguished by the greatly swollen base of the median and 

 submedian veins of the fore wings, the position of the second branch of the postcostal vein in the same wings arising beyond the 

 extremity of the discoidal cell, the strongly angulated base of the hind wings beneath, the very hairy [lalpi, and the slender acute simple 

 claws at the extremity of the tarsi. 



April 1. 1851. 5 E 



