344: ASELLID&. 
Squilla asellus. Dr Gezr, Ins. vii. t. 31, f. 1—20. 
Asellus vulgaris. LATREILLE, Hist. Nat. Crust. et Ins. vii. p. 359, 
t. 58, f. 1.  Dusmarzst, Cons. Crust. p. 314, 
t. 49, f. 1, 2. Mritnz Epwarps, Crust. iii. 
p. 146. Cuvier, R. An. (edit. Crochard) t. 70 
bis, f. 1. 
Entomon hieroglyphicum. Kun, Remarg. s. 1, Crust. fig. 5. 
Tus is a very common animal, occurring in fresh-water 
ponds and ditches throughout the kingdom. The male 
is much larger than the female. The head is about half 
the size of the following segment ; its underside is nearly 
covered by the large outer pair of foot-jaws, which con- 
sist of an oblong flattened basal joint (furnished on the 
outside, at the base, with a large semi-oval plate, Régne 
An. Ed. Crochard Crust., pl. 70 dis, fig. 1 a, and Treviranus 
Verm. Schr. t. xi. fig. 59 a, a), and five short terminal 
joints, of which the first is produced into a lobe at its 
inner extremity, and the last forms an acute finger-like 
joint. The mandibles (Treviranus o. ¢. fig. 63) are 
armed on the inside with a strong, horny tooth, and on 
the outside with a three-jointed palpiform appendage. 
The inner maxillz are described by the same author 
(fig. 60) as only having two terminal setose lobes, and 
the outer (fig. 61) as formed of two lobes, the inner 
one much more slender than the outer. The bilobed 
labium (fig. 62 z) lying between the base of the man- 
dibles, is described by Treviranus as the third pair of 
maxillee. 
The ventral surface of the segments of the body, in 
the males, is marked with strong transverse corrugations ; 
in the female, it bears the large ovigerous sac, within 
which the young are developed. The male, as is well 
shown by Treviranus o. c. fig. 65 p. and 66 z, is fur- 
nished with a pair of small and narrow curved horny 
lobes in the middle of the hinder segment of the body, 
