162 Mr. R. Shelford on new 
alar organs is much simplified and approximates to a radiate 
type, there being but little branching of the veins. The 
minute tarsal claws constitute another highly remarkable 
character. It is difficult to discover the affinities of a genus 
so aberrant as this; the biseriate arrangement of the tibial 
spines shows that it must be placed in the section of the sub- 
family which embraces Latindia, Stal, Paralatindia, Sauss., 
Homopteroidea, Shelf., &c.; but it cannot be regarded as 
closely related to any known genus. 
Subfam. PerrmsPH#eRIIN#. 
The Form of the Pronotum tn the Perispheriine. 
De Saussure and Zelintner, in their revision of the Peri- 
spheriine (Rev. Suisse Zool. vol. ili. 1895), have traced the 
evolution of the complex type of pronotum of such genera as 
Pilema and Cyrtotria [= Stenopilema, Sauss.] from a simple 
type. A summary of their conclusions may be presented 
here, and I have added some diagrammatic figures as a help 
to its elucidation. In a typical Blattid pronotum two areas 
may be distinguished, the disk and the lateral wings, which 
project on either side beyond the outer limits of the pro- 
sternum; the disk covers the head and on the underside is 
more or less defined by a pair of carine, known as the typical 
carine. In transverse section this form of pronotum may be 
represented as in Pl, IX. fig. 10, A, where a represents the 
disk, 6d the lateral wings, and cc the typical carine. In the 
genus Pronaonota (Pl. IX. fig. 10, B) the lateral wings are 
strongly bent downwards and an incomplete carina (d) on 
the deflected sides of the dorsal surface of the pronotum 
foreshadows the separation of the lateral wings from the disk. 
The separation is more or less complete in the genera Pilema 
and Cyrtotria (Pl. IX. fig. 10, C); the lateral wings in 
these genera now appear in side view as lateral bands bent 
down at a right angle, or at more than a right angle, to the 
disk of the pronotum, and their upper (morphologically inner) 
border is elevated, so that in dorsal view it appears as if the 
lateral borders of the pronotum had been simply reflected 
from below upwards. Such, however, is not really the case ; 
the carina on the pronotum of Pronaonota is the morphological 
equivalent of the upper edge of the lateral band of Pilema, 
and the lateral margin of the pronotum of Pronaonota is the 
equivalent of the lower edge of the lateral band of Pzalema. 
‘This lateral band is morphologically the lateral wing of the 
pronotum, which has become divided off from the disk, 
