48 RHOPALOCERA. 
ITHOMIA. 
Ithomia, Hiibner, Verz. bek. Schm. p. 9 (1816), partim. 
Dynothea, Reakirt, Pr. Ent. Soc. Phil. v. p. 222. 
Costa of secondaries of male rather highly arched; lower discocellular placed at 
nearly a right angle to the third segment of the median nervure, and bent to a small 
obtuse angle, where a rudimentary recurrent nervule is emitted; middle discocellular 
long; upper discocellular directed outwards, meeting the subcostal at a wide obtuse 
angle; proximal segment of subcostal slightly longer than the three segments of the 
median nervure ; costal and subcostal nervures enclose an elliptical space, the long axis 
of which is about one third the length of the subcostal nervure. 
Of the four species included by Hiibner in his genus /thomia, the most desirable in 
many respects to retain as the type of the genus is [thomia drymo, a species which has 
the neuration of the secondaries arranged as described above, and in which the peculiar 
elliptical space included between the costal and subcostal nervures is plainly indicated. 
This character is quite diagnostic of the genus, any member of which can at once be 
recognized by reference to it alone. 
The genus /thomia as thus restricted contains about thirty-five species, of very varied 
pattern of coloration and form of wing, but with a common type of neuration. Nine 
species are found within our limits, of which only two occur in Mexico and Guatemala, 
the rest being peculiar to Costa Rica and the adjoining countries, or else southern 
species passing within our boundary. 
1. Ithomia panamensis. (Jthomia lycaste, Tab. V. fig. 3.) 
Ithomia iphianassa, var. panamensis, Bates, P. Z. S. 1868, p. 244, t. 29. f.5'; Reak. Pr. Ent. Soc. 
Phil. v. p. 219°. 
Papilio lycaste, Fabr. Ent. Syst. iii. p. 161°? 
Ceratinia lycaste, Reak. J. c. p. 218, partim*. 
Ceratinia boucardi, Druce, Ent. M. Mag. xii. p. 126’. 
Alis nigris, basi fulvis, anticis plaga magna subtriangulari costam fere attengente, per cellulam transeunte et ad 
angulum analem extendente, maculis sex submarginalibus, et duabus (interdum quatuor) area apicali 
nigra positis, flavis, alarum basi fulvarum macula in cellule media et dimidio apicali posticarum nigris : 
subtus ut supra, sed maculis submarginalibus albis majoribus. 
Hab. Panama, Calobre (Arcé), Lion Hill (1 Leannan).—Co.omBia. 
Mr. Bates, who first described this insect from a single specimen sent us by James 
M‘Leannan!, considered it to be an extreme form of I. iphianassa; but an examination 
of a large series of examples shows that the peculiarities of LZ. panamensis are shared 
in common by all the individuals of the district, and that it is really a sufficiently well- 
marked form to deserve a name. The large triangular yellow spot on the middle of the 
primaries at once distinguishes it from all its allies. In coloration it has the pattern of 
Callithomia panamensis, Ceratinia cleis, and Mechanitis macrinus—all Panama species. 
