CANTHOOAMPTUS. 57 



5. CANTHOOAMPTUS NORTHUMBRICUS, nov. sp. PI. XLV, 



figs. 114. 



Body robust ; abdomen of the female 4-, of the male 

 5-jointed. Anterior antenna (fig. 1) as long as the 

 first segment of the body, 9-jointed, almost exactly 

 similar to that of C. trispinosus. Secondary branch of 

 the posterior antenna very small, 1-jointed. Mandible 

 (fig. 4) very slender, palp minute. Second foot-jaw and 

 first pair of feet (figs. 7 and 8) as in C. trispinosus. 

 Inner branches of second, third, and fourth pairs of 

 feet 2-jointed (fig. 9), the first joint very small. In 

 the male the inner branch of the third foot (fig. 11) is 

 3-jointed, and the middle joint is produced downwards 

 into a long crooked spine ; the last joint has three 

 apical setse. Basal joint of the fifth foot in the female 

 broad, the inner segment not at all produced, but 

 fringed with six stout plumose setse; second joint 

 broad, quadrangular (fig. 12), and armed with five 

 stout plumose setse, one of which is much longer than 

 the rest ; in the male the inner segment of the basal 

 joint (fig. 13) has only three setse ; the second joint 

 small, sub triangular, and having a setose armature 

 somewhat similar to that of the female. The hinder 

 margins of the abdominal segments (fig. 14) are ser- 

 rated with two rows of small teeth, and the anal oper- 

 culum is also sparingly denticulated (fig. 14 a). Length 

 -sM;h of an inch (-9 mm.). 



o \ / 



This species I have found only sparingly in the lake 

 at Bolam, Northumberland. 



