52 THE ROYAL SOCIETY OF CANADA 



each of the outer pair has a seta and of the inner pair three, nearly 

 equal in length. Abdomen very short, only one-fifth as long as broad. 

 Anal laminee widely separated, small, each supplied with five setae, of 

 which the three inner are much longer than the two outer Egg-strings 

 two-thirds the length of the body, with about 50 eggs in each string. 



First antennae projecting beyond the carapace, the terminal 

 joint slender, slightly longer than the basal joint. Second antenna 

 with the terminal claw long, slender and abruptly bent near the end; 

 the basal joint is provided with a short spine. Maxillary hook stout, 

 tapering rapidly to a sharp point, strongly curved. First maxilla 

 small, with both rami sharp- pointed, the inner much smaller than the 

 outer. Just posterior to the outer portion of the maxilla there is a 

 papilla provided with two spines, an inner, shorter and an outer, 

 much longer. Furca, with rami rounded at the tip, but little sepa- 

 rated at the base, looking like the fangs of a premolar tooth. The two 

 joints of the second maxilla are nearly equal in length, both joints free 

 of spines. Maxillipeds short and stout in both joints, no spines. 



In the first swimming leg, the spine on the basal joint is strong; a 

 small spine is present at the antero-dorsal margin of the second joint. 

 Basal joint of the second leg with a strong spine on the posterior 

 border. The rami of the third leg are not widely separated; the spine 

 at the base of the exopod is as long as the breadth of the joint. Fourth 

 leg stout; a short spine at the distal end of the basal joint; second joint 

 with a short claw; third joint larger than the second, with a strong 

 spine; terminal joint the shortest, with four spines, the inner short, 

 the next one long, the fourth short but longer than the first. 



Total length 3-68 mm., length of carapace 2-14, width 2-32, 

 length of genital segment 1 -2, width 1 -4, length of egg strings 2-3. 



Male: Body about half the length and half the width of the female. 

 Carapace slightly longer than broad, rounded posteriorly and anter- 

 iorly. Posterior sinuses narrow and deep; lateral lobes wide and 

 blunt; median lobe rounded, half the width of the carapace. Free 

 segment broad but narrowed where it joins the other segments, 

 relatively long. Genital segment broader than long, rounded anter- 

 iorly and posteriorly; each of the outer pair of legs is provided with 

 four setae, the innermost one being the longest and the third, second 

 and fourth following in order. There are three setae on each of the 

 inner pair, of which the innermost is long, the next one much shorter 

 and the third short and weak. The anal laminae are well separated; 

 each is provided with three strong setae, the two inner being nearly 

 equal in length, longer than the third, and three very small setae, one 

 inside and two outside of the other three. 



