324 ASELLIDJ;. 



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 antennae. 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 praeditum 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. Kroyeri ; 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. 



