Mr. R. Shelford’s Studies of the Blattidex. 459 
ii. DE GEER’s COLLECTION. 
As already stated, De Geer in his “ Mémoires pour servir 
a histoire des insectes,” vol. ii (1773) enumerates twelve 
species of Blattidze, six of which are described as new, 
v1Z. :-— 
Blatta pensylvaniea. 
Blatia abdomen-nigrum. 
Blatta livida. 
Blatta rufa. 
Llatta grisea. 
Blatta minutissima. 
The remaining six species are Linnzan species, but new 
names are given to two, even though De Geer fully recog- 
nised the specific identity of his species with those of 
Linneus. 
The collection is now at Stockholm in the Riks Naturhis- 
toriska Museum, and with the exception of one specimen 
is in a good state of preservation. I am indebted to Dr. 
Y. Sjostedt for permission to make a careful examination 
of this very interesting collection. The following is a 
catalogue of the specimens with annotations :— 
1. Blatta culinaris, De Geer, op. cit. p. 530, pl. 25, ff. 1-7. 
This is the Blatta orientalis of Linneus; 2 $2Z,1 ¢, 
and also | larva of Pycnoscelus surinamensis, L. 
2. Blatta lapponica, De Geer, op. cit. p. 533, pl. 25, ff, 8-12. 
= Kctobius lapponicus, L. 
otaeee 
3. Blatta kakkerlac, De Geer, op. cit. p. 535, pl. 44, ff. 1-3. 
= Periplaneta americana, L. 
Lea se 
From 8. America (Rolander.) 
4. Blatta pensylvanica, De Geer, op. cit. p. 537, pl. 44, f. 4. 
= Ischnoptera pensylvanica, De Geer. 
es 
The species has been recognised and correctly deter- 
mined by all subsequent authors. 
From “ Pensylvania” (Acrelius). 
