MONTAGUA MARINA. 59 



of the peduncle reaches beyond the extremity of the 

 peduncle of the superior. The last joint is rather more 

 than half the length of the preceding, and the flagellum 

 is not longer than the last joint of the peduncle. The 

 mandibles are long, narrow, and furnished with a minutely 

 serrated cutting margin. It is also furnished with a mi- 

 nute secondary moveable plate having a serrated edge. 

 This plate we believe to be common to the genus, but is 

 not figured in the preceding species, from the probable 

 fact that it exists only upon one mandible, the other 

 being without it, as shown by Mr. Westwood's dis- 

 sections, published by Professor Bell, to be the case 

 in Stegocephalus ampullus, the typical genus of this 

 subfamily where it exists upon the left mandible only. 

 The pair of foot-jaws have all the joints subequal, 

 the sixth being slightly longer than any of the others. 

 The first pair of legs are short and slender, having the 

 fourth joint anteriorly produced into a considerable pro- 

 cess beneath the fifth. The fifth, or wrist, is nearly as 

 long as the sixth, or hand, which is of a long elliptical 

 form, having the palm convex, not defined, but armed 

 with a few cilia. The second pair of legs are much 

 longer, larger, and more powerful than the first. They 

 have the fourth and fifth joints very short, but both 

 anteriorly and inferiorly produced to an angle. The 

 hand is long; the upper margin forming an arched line 

 continuous with that of the wrist ; the palm runs 

 diagonally with the axis of the hand, nearly straight 

 to its base beneath, where two small tubercles, armed 

 with a single blunt spine, carrying a small subapical 

 bristle, define its limits. Throughout its entire length 

 the palm is furnished with a row of equidistant solitary 

 cilia. The finger is as long as the palm, somewhat 

 curved, and tapering to the point, which, when closed, 



