NOTHRUS PALUSTRIS. 495 



the mm., and about twice tlie width of the dividing 

 depressions). 



Shape nearly oblong. 



Cephalothorax more than a fourth of the whole 

 length. Rostrum rather pointed, widening gradually to 

 the first pair of legs, lateral margin straight, but there 

 are two slight indentations in it on each side. There 

 are deep and sharp excavations immediately behind 

 the rostrum for the insertion of the first pair of legs ; 

 behind them the cephalothorax increases considerably 

 in breadth, but has a rounded lateral margin ; it is 

 nearly as wide as the progaster, where they abut on each 

 other. There is a rough transverse ridge across the 

 base of the rostrum, probably the homologue of a 

 translamella, and behind this are two large, parallel, 

 longitudinal ridges or rolls, a transverse section of 

 one of these would be almost circular. These rolls end 

 posteriorly in domed elevations which bear the pseudo- 

 stigmata near their posterolateral parts. These 

 pseudo-stigmata are rather large and almost upright. 

 Pseudo-stigmatic organs very long, as long as the 

 cephalothorax or longer, filiform, directed almost out- 

 ward, but usuallij doubly curved, the proximal curve 

 concave, and the distal convex as seen from the front. 

 Interlamellar hairs short, spike-like, very close to the 

 pseudo-stigmata. No first tectopedium ; the second 

 forms a blunt bifid projection behind the insertion of 

 the first leg. Rostral hairs short and curved. Lamellar 

 hairs, or what represents them, short, straight, near 

 together, directed straight forward. Apodemata joined 

 to the sternum. 



Legs long for the genus, moderately thick, gradually 

 tapering; most joints with a slight median constric- 

 tion, behind which the thick hairs are inserted. 

 Femora of the two front pairs with thin, short, proxi- 

 mal ends set at an angle of about 45°. Genuals as long 

 as the tibiae. Tarsi far the longest joints ; gradually 

 diminished toward the distal ends, which are rather 

 blunt. The fourth legs of this species and the allied 



