48 THE CANADIAN ENTOMOLOGIST. 



mucro with four teeth, the first at the base of the second, the 

 second and third subequal, the fourth smaller, arising at the 

 side ; dentes longer than the manubrium ; ocelli sixteen, eight 

 on each side of the head 4. 



Inferior claw without a tooth on the inner margin, inner margin 

 strongly, roundly, dilated ; superior claw without teeth on the 

 outer or inner margins ; tibiae with a single tenant hair ; mucro 

 with three teeth, the first at the base of the second, the second 

 and third subequal in length, vertical ; dentes twice the length 

 of the manubrium ; body brownish, in some specimens with a 

 slight indication of a median dorsal line ; legs and furcula 

 yellowish ; eye spots black ; antennae twice the length of the 

 head, the apices of the segments purplish, at base greenish. 

 The typical specimens are from Salem, Massachusetts, and 

 Waco, Texas. The Massachusetts specimens belong to Isotoma 

 viridis, Bourlet, an European species, while the specimens from 

 Texas are distinct, and Dr. Packard's name is retained for this 

 form tricolor, Pack. 



4. Dorsum with a distinct median black line 5. 



Dorsum without a median black line 6. 



5. Yellowish, median and lateral black lines distinctly marked, median 



black line without lateral dilations in the third and fourth abdom- 

 inal segments. Habitat — Europe, Asia, Africa, and North 



America *palustris, Muller. 



Yellowish, median black line with distinct lateral line-like dilations 

 in the third and fourth abdominal segments ; sides of the thoracic 

 and abdominal segments clouded, darker near the margin. 

 Habitat — Europe ^paiusiris aquatilis, Muller. 



6. Segments yellowish, with a wide transverse black band, covering the 



anterior two-thirds of each segment. Habitat — Boreal 



Europe ^palustris balteata, Reuter. 



Segments entirely of one colour 7. 



7. Entirely dilute greenish, immaculate. Habitat — Boreal 



Europe '^palustris prasina, Reuter. 



Entirely reddish-violaceous ; antennse and feet blue-black. Habitat — 

 Boreal Europe ^palustris fucicola, Reuter. 



*Species not seen. 



