Mr. R. Shelford’s Studies of the Blattide. 463 
Total length 24:1 mm.; body-length 20°-4mm.; tegmina 20°5 mm.; 
pronotum 5 mm. x 6 mm. 
Recorded from Surinam. 
10.Blatta nivea, L., De Geer, op. cit. p. 540, pl. 44, f 10. 
= Panchlora nivea, L. Type. 
(syn. Panchlora virescens, Thunb.) 
ee 
The genus Panchlora includes several species described 
by the older authors, e.g. viridis Fab., hyalina Stoll, 
virescens Thunb., exoleta Burm., viridis Burm., chlorotica, 
Pall.; to determine these with accuracy or to fix their 
synonymy is a matter of impossibility unless all the types 
are critically examined. De Saussure and Zehntner 
in the “ Biologia Centrali-Americana. Orthoptera,”’ vol. 
i, p. 90-92, have drawn up a synoptical key to the species 
of Panchlora without consulting any of the older types ; 
such a key certainly enables the student to give a name 
to his specimens, but by no means does it follow that 
these names are correct, in fact it must be a matter of 
pure chance if the use of such a key enables the system- 
atist to identify any one of his specimens with accuracy. 
A good example of this is shown in the species under 
notice, P. nivea, L.; the key of de Saussure and Zehntner 
accidentally is correct in diagnosing P. virescens Thunb., 
but P. nivea, L. is situated in another part of the key; 
yet these two species are the same, as I have discovered 
from an examination of De Geer’s specimen which I 
accept as the Linnean type and of Thunberg’s type. The 
identification of the species of Panchlora is most difficult, as 
they resemble each other very ciosely and present scarcely 
any characters that do not vary to such an extent that 
they are practically useless for purposes of discrimination. 
One character however appears to be of some importance, 
viz. the form of the cerci, and the size of their apical joints 
when viewed from below. In a species which I identify 
provisionally as P. antillarum Sauss., the cerci are broad, 
somewhat spatulate and with the last two joints much 
enlarged ; in P. viridis Fab., the cerci are lanceolate with 
the last two joints enlarged ; in P. nivea, L., the cerci are 
lanceolate with the last joint only enlarged. This charac- 
ter occurs in both sexes, and taken in conjunction with 
