1945] Notes on Neotropical Plebejinoe 45 
The majority of neotropical Plebejinoe possess a sagum or 
rudiments of one. It is completely absent only in Itylos as it is 
absent in all palaearctic, nearctic and palaeotropical species. This 
structure can be loosely defined as a fultura superior in relation 
to the furca (fultura inferior), but its function, if any, is ob- 
scure. One is inclined to assume that at the time of the invasion 
of the neotropical region from the north there existed Eurasian 
forms with rudiments of a sagum (possibly allied at that stage 
to the anellus now possessed by the Catochrysopinoe and other 
subfamilies) which in the subsequent flurry of hectic central 
palaearctic evolution was lost (and had been already lost by the 
ancestors of Itylos ) but in the comparative peace of the neo- 
tropics continued to develop owing to that peculiar evolutionary 
inertia which in the absence of any obstruction keeps a struc- 
ture tending to its maximum along certain inheritable lines. 
In all (80 to 100) Old World and nearctic species the valve 
is of a very constant general shape. 1 Among the 19 neotropical 
species known, “normal” shape occurs in 11 species. The rest 
show four types of variation unparalleled elsewhere. In this 
respect the peculiar reduction of the valve in Parachilades , 
Pseudochrysops and Cyclargus would seem to be a case of 
stunting rather than the retention of a very short valve from 
which the normal elongate structure of the subfamily was 
evolved (“pulled out” as it were). In regard to H. hanno and 
ramon one suspects that the unusual shape is due to the irregular 
dwarfing of a ceraunusAIke valve which had initially attained 
a very full shape (suggested by some of the Central American 
specimens), the “keel” in hanno and ramon being probably the 
remnant of an ample lower margin. 
The underside wing pattern of neotropical Plebejinoe falls 
into two main types: catochrysopoid and ityloid. The cato- 
chrystopoid type ( Pseudochrysops , Cyclargus , Hemiargus and 
Echinargus ) is shared in the Old World by the small Palaeo- 
tropical section ( Chilades 2 and less strikingly, Freyeria) and 
in result, certain Hemiargus and Echinargus forms are remark- 
*A slightly aberrant structure occurs only in Chilades galba and Albulina 
( auct ) felicis and this leads to a false resemblance to certain Glaucopsychince. 
2 Which, moreover, in Chilades cleotas (a species ranging from the Malay to 
the New Hebrides, at least) evolves a likeness to Talicada nyseus (Everince) , the 
behavior of which (deducible from a note in Moore) is that of a “protected” 
species. Freyeria on the other hand tends, mainly owing to its small size, to a 
Brephidium aspect. 
