518 EXTERNAL ANATOMY OF INSECTS. 
ten*, Others, again, have more than eleven joints: 
Cebrio Gigas, Chrysomela stolida, some Saperde, and 
several others, have /welve. In Prionus imbricornis the 
female has xinctcen, and the male twenty>. Rhipicera 
marginata has thirty-two* ; and ina New Holland species 
of this genus I counted thirty-eight. In the Orthoptera 
I can trace no general law in this respect. In Locusta 
in some species you may count fourteen joints, in others 
sixteen, and in others ¢wenty-five. In one, which appears 
to be a pupa, I found only ¢hirtcen. In Mantis they 
exceed thirty; but in Blatta, from between thirty and 
forty, they reach nearly one hundred and fifty ; often 
varying in number in different individuals of the same 
species. The order Hemiptera exhibits two peculiar 
types of antenne, which, with some exceptions, distin- 
guish the two natural sections into which M. Latreille 
has judiciously divided it. In the Heteropterous section 
they are wzthout a bristle at their end; and in the Homo- 
pterous one, with the exception of Aphis, Thrips, &c. 
they Aave one. In the genera of both these tribes, the 
number of joints varies in these organs. Thus, exclu- 
sive of the seta, in Flata and Cixius there are only two 
joints; in Galgulus, Fulgora, and Cercopis, there are 
three; in Lygeus, Coreus, &c. there are four ; in Scutellera, 
Pentatoma, Cicada, there are five’; in Aleyrodes there 
are szx ; in Aphis, seven ; in Thr iggss eight ; in Livia, ten, 
the last of which is terminated by two bristles *; and in 
Coccus, eleven. 'The Neuroptecra order, as it stands at 
+ Prate XXY. Fic. 1. > Prater XI. Fic. 12. 
* Linn. Trans. xii. t. xxi. f. 3. 
‘ Latreille says six, but only five are discernible; the three last 
form a kind of bristle. 
* Latr. Fourmis, 323. 
