Or 
Gencra and Sp cies of Blattides. 17 
Genus PLATYSILPHA, nov. 
Allied to Derocalymma, Burm., but much broader, pro- 
notum about twice broader than long. @ with tegmina 
reduced, quadr ate, extending to the Fiddle of the second 
paoninial tergite, ‘marginal field very broad, Wings rudi- 
mentary. Meso- and inetanotum only half the breadth of the 
pronotum, and first abdominal segment narrower than second ; 
subgenital lamina transverse ; styles absent. 92 very like 
2 of Derocalymma, but broader and oval. 
Type. Pertspheria mur rena, Walk. 
The male of this species, when the tezmina are removed, 
presents the remarkable outlineshown in the figure, sugeesting 
that the flattened broad insect has developed from a narrow 
form such as Derocalymma porcellio, Gerst., the mesonotum, 
metanotum, and first abdominal seement retaining the primi- 
tive narrowness. ‘The marginal fields of the tegmina have 
broadened relatively much more than the discoidal field, and 
it is these which fill the gap between the posterior margin of 
the pronotum and second abdominal tergite ; the teemina are 
capable of only the most restricted movement outwards, and 
in the living insects are doubtless never moved at all. 
In the female, owing to the absence of tegmina, the thoracic 
and abdominal segments are all equally broad; it is the 
broadening of the fegmina in the male which appears to have 
prevented the broadening of the segments that they cover. 
Platysilpha murina, Walk. (Pl. X. fig. 20.) 
Perispheria murina, Walker, Cat, Blatt. Brit. Mus. p. 178 (1868). 
3. Fuscous, with fine scale-like pubescence above. Head 
and antenne piceous ; eyes approximated. Pronotuin poste- 
riorly truncate ; posterior angles acute, disk cucullate, margins 
lamellar, anteriorly slightly carinate. Scutellum prominent. 
Tegmina castaneous, rugose, posteriorly emarginate, radial 
vein beneath prominent, keeled. Wings shorter than 
tegmina, infuseated. Hight abdominal tergites visible, first 
to sixth divided by a transverse suture into a broad anterior 
portion and a narrow posterior portion ; posterior angles of 
all the tergites produced. Supra-anal lamina quadrate. 
Cerci very short. Abdomen beneath piceous, nitid ; sternites 
failing to reach Jateral margins owing to overlapping of the 
ter gites ; ; subgenital Lavan FEMS: Legs piceous. 
oF Similar to 6, but with a rust-red pubescence above ; 
mesonotum, metanotum, and first abdominal segment not 
coarctate. ’Subgenital lamina ample. 
