458 Mr. R. Shelford’s Studies of the Blattide. 
them.” Whether my supposition that De Geer lent some 
of the specimens in his collection to Linnzus for description 
is correct—and it must be admitted that there is a degree 
of probability in its favour—or not, I would venture to 
suggest that the specimens of swrinamensis, americana 
and nivea now in the De Geer cabinet be selected as 
the types of the Linnzan species; otherwise these species 
must remain without typical specimens, for if these 
specimens are not the actual types then the actual types 
are irrevocably lost. The specimen of oblongata in 
De Geer’s cabinet cannot be chosen as the type of the 
species, for, though it is ina fragmentary condition, enough 
remains to show that it does not in the least correspond 
with the Latin diagnosis of Linnzus or with De Geer’s 
description in French or with his figures. In other words, 
this is not the actual specimen on which both Linnzus and 
De Geer based their descriptions; that specimen must 
have been lost or destroyed accidentally, and the existing 
specimen subsequently placed under the same name, either 
by De Geer or perhaps still later by some one else. The 
discrepancy between the descriptions of oblongata and the 
existing specimen does not invalidate my view as to the 
identity of the Linnzean types, for the diagnosis of Linnzeus 
tallies perfectly not only with De Geer’s description but with 
his figure. It is noteworthy too that in the case of the 
other three species the Linnean diagnoses agree perfectly 
with De Geer’s specimens, figures and descriptions ; the 
Latin diagnoses are of course much shorter than the French 
descriptions, which are therefore not mere translations, but 
additional and amplified diagnoses. 
As to oblongata there seems nothing for it but to regard 
the species for the present as uncertain; it has not been 
recognised with accuracy since it was described, for the 
Llatta oblongata of Serville and the Thyrsocera oblongata 
of Brunner and de Saussure is quite a different insect, 
to be identified probably with the Slatta intercepta of 
Burmeister. The species described by Walker as Pseudo- 
mops inclusa (= amena Sauss.) is evidently closely allied 
to oblongata L., and a long series of specimens might show 
that Walker’s species was merely a varietal form of 
oblongata. 
The other Linnzean species which had not been recog- 
nised with certainty by later authors, Blatta nivea, will 
be discussed in the next section of this paper. 
