132 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. 
The mandible is a flattened toothed plate, bearing a two-jointed ° 
palp on one side and a blunt process on the other. 
The first maxilliped is short and bears claws and spines. The 
second maxilliped is simple, three-jointed, and has a claw at the end. 
The first pair of feet are biramose, each ramus being three-jointed; 
the outer ramus is shorter than the inner. The inner ramus of the 
fourth foot is two-jointed. In the male the inner ramus of the third 
foot is modified into a sort of grasping organ. ‘The fifth feet are com-: 
posed of two flat joints, larger in the female than in the male. 
The first abdominal segment of the male carries a pair of three- 
spined processes. The last abdominal segment bears two stylets, each 
terminated by two long sete, one being longer than the abdomen and 
longer in the male than in the female. 
* Canthocamptus illinoisensis Forbes. 
PLATE XXIX, Fias. 1-5. 
This robust and pretty species was first taken near Minneapolis 
by Mr. A. W. Jones, a student of the University, who found it in a 
peaty ditch. Forbes’ description is appended. 
‘‘Length 1.0 mm. Head and first segment united; five abdominal 
segments in male, four in female. The suture between the first and 
second segments is not wholly obliterated above in the female. 
‘“‘Tast abdominal segment is deeply and acutely emarginate. 
Branches of furca as wide as long, inner bristle plumose, a little longer 
than abdomen; outer plumose only on outer side, about half the length 
of the inner. Thesecond to fifth abdominal segments have each a row 
of spinules along ventral portion of posterior. 
‘‘Male with anterior antennz composed of seven joints, the fourth 
joint very short. The front outer angle of the third is produced, the 
blunt process bearing three long bristles surrounding a slender olfac- 
tory club which is as long as the three following joints. The penulti- 
mate joint bears a strong spine or slender appressed process at the 
middle of its posterior margin. ‘The five outer joints constitute the 
grasping organ. The posterior antenne bear five long bristles at tip, 
three of which are made prehensile by the occurrence of from eight to 
twelve short articulations in the middle of the hair, allowing it to be 
bent forward. At the base of these articulations on the outer bristle 
are two short spinules. Two nearly longitudinal rows of five or six 
strong, short spines each appear on the under surface of the outer 
joint of the antennule. The secondary flagellum, borne as usual on 
the middle of the basal joint, is not articulated, and bears four long 
bristles, two terminal and two on distal half of inner side. The out- 
line of the mandible is exactly like that figured by Claus, but it bears 
’ 
