236 
CRUSTACEA. 
They inhabit retired and obscure places, cellars, fissures in walls, old 
buildings, under-stones, &c., &c. They feed on decaying vegetable 
and animal matters, and seldom issue from their retreat except in 
rainy weather. They move but slowly, unless they are alarmed. 
The ova are inclosed in a pectoral pouch. The young, at l)irth, have 
one thoracic segment less than the adult, and consecpiently have 
but twelve feet. They are no longer employed inmcdicine*. 
PORCELLIO, Lat. 
The Porcelliones differ from the Onisci in the number of joints 
that compose the lateral antennee, which is only seven. In their 
other characters they arc alike f. 
There, as in 
Armadillo, Lat. 
The posterior appendages of the body do not project ; tbe last seg- 
ment is triangvdar; a little lamina resembling a reversed triangle, or 
widest and truncated at the end, formed by the last part of the late- 
ral appendages, fills on each side, the space between that segment and 
the preceding one. I'he lateral antennee have but seven joints. The 
superior subcaudal scales exhibit a range of small holes j;. 
vSECOND GENEllAE DIVISION. 
ENTOMOSTRACA. 
Under this denomination, which is taken from the Greek and sig- 
nifies Insects with shells, Othon Frederic Muller comprises the genus 
Monoculiis of Linnaeus, to which we must add some of his Lornae.ee 
His investigation of these animals, the study of which is so much the 
more difficult as they are mostly microscopic, and the observations of 
Sclaeffer and of M. Jurine, Sen., have excited the admiration and 
secured the gratitude of every naturalist. Other but i)artial labours 
such as those of Randohr, Straus, Herman, Jun., Jurine, Jun., 
A. Brongniart, Vistcr Audouin, and Milne Edwards, liave extended 
our knowledge of these animals and particularly of their anatomy; 
* Oniscu, murarius. Cuv., .lourn. il’Hist. Nat., II, xxvi, 11, 13; LcClo- 
por/e orfiinaire, Geoif.. Insect. II, xxii, 1 ; Clojiorte aselle, Deg., Insect. VII, xxxv. 
3 ; Desmav. Consid., XLIX, 5. 
'j' Oniscus aseJhis, Cuv., Ib.; Panz., Faun. Ins. Germ.,IX, xxi ; Cloporte ordinaire, 
var. C, Geoff. ; — Porcellio locvis, Latr. ; Cloporte ordinaire, var. B, Geoff. 
X Qnisms armadillo, D. •, Cuv., Ib., 14,15; Oalscifs ciaemis, Panz., Ib., Fascic. 
LXII, xxii ; — Oniscus variegalns. Till., Entom., IV, xi, 16 ; Armadillo pustule, Dcs- 
mar., Consul., LXIX, 6 ; — Armadille des boufupies, Dumer., Diet., des Sc. Nat., 
Ill, p. 1 17, a species from Italy formerly employed by the apothecaries. 
