324: ASELLID A. 
exceeding the whole animal in their length, with a four 
or five-jointed peduncle (of which the two last joints 
are long and subequal), and a multiarticulate flagellum 
half the length of the entire antennz. ‘The segments of 
the body are subequal in length, but the first and 
seventh are often shorter than the rest: in the males, 
the body is narrow, with the sides parallel; but in the 
female, the outline of the animal is ovate, or pear- 
shaped. The foot-jaws consist of a large basal joint, 
armed at the base with an elongated triangular scale, and 
produced on its inside into a flattened blade, rounded at 
its extremity and ciliated, and followed by four distinct 
joints, gradually becoming more slender, and furnished 
with strong bristles at their distal extremities. The 
mandibles are robust, and armed on the inner edge with 
a strong molar tooth, and at the base, on the outside, 
with a three-jointed palpiform appendage. The fore legs 
are short but strong, and furnished with a subcheliform 
hand, whilst the six remaining pairs of legs are very 
long, and terminated by two long, slender, simple ungues. 
The tail consists of a single piece, of a flattened ovate 
form, narrower than the segments of the body. We 
presume that in this genus the sexes are distinguished 
by the same condition of the branchial plates as 
we have above stated to occur in several of the other 
genera of this family. Kroyer, in his characters of the 
genus, says ‘‘unica infra lamina preditum tectoria,” 
whilst H. Goodsir represents the ‘ abdominal plate,” 
as he terms it, as composed of two long and narrow 
pieces soldered together along their inner margins, 
copied in our cut of M. Kréyeri ; but on referring to 
Kroyer’s original description, we perceive that it is 
taken from the female of M. Boeckii, whilst H. Goodsir’s 
description is taken from a male animal. 
