156 Mr, W. S. MacLeay on ihe Anatomy of the 
and a body consisting of twelve segments. It follows of course that the 
first pair of feet, as they are called in all octopod Arachnida, whether 
spiders, scorpions or mites, are nothing else than the labial palpi of 
winged insects.* This is, itis true, a novel mode of viewing Crustacea 
and Arachnida, but as it leads to some most curious results, I shall prove 
its accuracy at afuture opportunity, and shew in what the variations from 
this type really consist. My business at present must be with winged in- 
sects, in which the same rule not only holds good but is typical. 
Let us observe a Phasma, where the female is apterous and the male 
winged. In many females of this genus we may perceive the rudiments 
of the wings, and consequently the inspection of a female will point out 
to us the structure of the male, considering this last as a perfect winged 
insect. Well then the female Phasma shews nine abdominal segments, 
three thoracic anda head. The females of certain Blatte are apterous, 
and in the island of Cuba there is a large insect of this genus to be found 
under stones in woods, whose four wings are formed, but so short and 
truncated as to render the possessor incapable of flight. Such insects 
will also prove a winged Blatta to be composed of the abovementioned 
thirteen segments. The same results are derived from the examination 
of the larve and females of Drilus and Lampyris. It is true that some 
of the abdominal segments become more or less confluent in certain in- 
* A careful study of the very curious and distinct order of Arachnida, and 
in particular of the genera Mygale, Scorpio, Phryne, Galeodes, Gonyleptes, 
and Chelifer, ina live state, has convinced me that M. Latreille’s idea of these 
insects being supplied with antenne is correct. Another certain character of 
the class is to have the labial palpi converted into a pair of feet which are ge- 
nerally of the same form as the six true feet. Mr. Kirby’s ingenuity detected 
(see Int. to Ent. Vol. IV., p. 387.) what are commonly called the first pair of 
feet in Scorpions and Spiders, to represent the palpi of winged insects ; but he 
appears to consider then) as the maxillary palpi, whereas they in reality repre~ 
sent the labial. A still greater mistake, indeed an unaccountable one in a per- 
son of his science, has been his not perceiving that the same rule holds good 
in the Acaride, and his placing these most evident Arachnida with hexapod 
Ametabola, to which they have no earthly relation, unless perhaps it be that of 
aslight, and a very slight, affinity of transultation. 
