238 Prof. J. C. Schiódte on the Morphology 
mgr t et the number and position of the spi- 
cles in Heteroptera, Scarcely two authors agree on this 
sitit: and ri is no vestige of any one having so much as 
thought of any fixed rule being observable in this respect. 
If, for instance, we turn to "the newest manual * (Fieber's 
well-known and indispensable work on the Rhynchota of 
Europe), we read (p. 9) t “ The spiracles of the body, 
stigmata, appear only now ngs then clearly on the dorsal 
rings, and with the exception of some genera of Hydroco- 
rides, always to be perceived on the sides of the ventral sur- 
face as on perforated knobs (Taf. i. fig. 30,7). The spiracles 
of the thorax are placed on the sides of the metathorax, and 
xm an elongated slit, surrounded by a thick or lamelliform 
margin (Taf. i. figs. 1; 2, 30, p), which sometimes terminates 
on the outer side in a corniform prolongation (some Zerytidi, 
Oxycareni). More rarely, each segment of the thorax has its 
own spiracle.” A little before, in treating of the prothorax 
(p. 7), it is stated :—“ The prothorax rarely has a spiracle”; and 
in treating of the abdomen (p. 8), “The connecting marginal 
piece, connexivum, which is turned round from the ventral 
surface to the back (Taf. ii. fig. 2, b), carries the dorsal stig- 
mata, which in Nepa particularly clearly are covered by a 
membrane." According to the statement on p. 5 the stigmata 
to p. 9, sometimes on the back, but always on the ventral 
side ; the thorax, we are to understand, has only sometimes 
spiracles between the prothorax and mesothorax, more rarely a 
pair for each segment, but always a pair on the metathorax. 
Any reader, however, who understands that the last statement 
Eia as all de contain in this respect dincdddMo the ime na of 
Insecta and Articulata in general is a confused mixture of a little that is 
true mass of yide Pus no one pu undertaken to verify 
statements and e ES cete mprehensive morphological 
oint of view, my eyen d enk regard to the manual of 
sat to whom, however no lame Ares erar. as a better result could not 
ttained without new and comprehensive investigations 
E 
