46 THE ROYAL SOCIETY OF CANADA 



segments decreasing regularly in width, each of them being nearly 

 three-fourths of the one preceding; the fifth is about one-fourth the 

 width of the carapace. The second segment is one-half the length 

 of the céphalothorax, the third slightly longer, the fourth about half 

 the length of this and the fifth about one-third the length of the fourth. 

 Genital segment slightly wider than the fifth segment, nearly the 

 same width throughout; the sixth pair of legs is represented by 

 papillœ, each bearing three setœ. Abdomen not very distinctly 

 separated from the genital segment, and not definitely divided into 

 segments, tapering gradually, with a lateral seta on each side where it 

 joins the lamina?; the anal lamina? are not distinctly separated from 

 the abdomen, rather slender, well separated from each other; one 

 short lateral and three terminal seta?, of which the inner is quite 

 long, as long as the abdomen and anal lamina. Egg strings elliptical, 

 nearly two-thirds of the total length of the body, with 5 or 6 vertical 

 and 24-26 horizontal rows of eggs. 



First antennae showing the joints distinctly, the division of the 

 two basal joints being indicated; heavy setae appear around the margin 

 of the first three joints, becoming more nearly parallel with the 

 antennae the farther from the base, the most distal one is longer and 

 stouter than the others; there are two small setae at the end of the 

 fourth and fifth joints and four at the end of the terminal joint; from 

 the second joint the tactile hairs project forward, the proximal one 

 two and a half times, and the distal one twice the length of the setae. 

 Second antennae with the terminal joint roughened; it is provided 

 with three claws of unequal length, and a rough finger-like process, 

 Labrum with length two-thirds width, a process projects at each side 

 in front of the base of the mandible. Mandible small, smooth, 

 projecting backward along the surface of the labrum. First maxilla 

 with one longer seta extending diagonally to the median line and two 

 shorter ones running backward side by side. Second maxilla with 

 large base and broad terminal joint, reaching horizontally almost to 

 the median line, blunt at the end and supplied with several setae. 

 Maxilliped with basal joint passing directly outward, second joint 

 somewhat larger than the basal, passes outward in continuation of the 

 first joint and then well forward so as to be well away from the re- 

 mainder of the mouth parts, with a single large plumose seta at the 

 distal end, curved like the joint and reaching backward past the 

 proximal end of this joint; terminal claw S-shaped, passing backward 

 to lie parallel to the second joint and to the seta of this joint, a little 

 more than half of the length of the seta, provided with a long straight 



