OF WATERBUGS, ESPECIALLY OF CORIXIDAE. 41 



consisting of about twenty short suboval pegs rising from the base 

 and running close to the lower margins, the other consisting of fifteen 

 ^milarly-shaped ones along the upper margin nearer the apex. 



Species 3. C, caledonica Kii-kaldy. 

 (= cognata in Saunders, I.e.) 



The only structural difference between this and praeusta that I 

 <;an find is that the palae are not so suddenly dilated at the apex 

 in the male, and there are only about nine pegs in the upper 

 row, but this former character is a little variable in the latter 

 species. Unfortunately, I have only been able to examine a 

 single specimen. 



Species 4, C. concinna Fieber (fig. 14). 



Palae, <$ , simple, cultrate, with about 40 pegs, blunt and suboval 

 basally, gradually elongating towards the apex. 



Subgenus 3. Arctocorisa Wallengren. 



Face as in Callicorixa. Strigil present on right side ; stridulator 

 and stridular area present (^ . Palae $ , cultrate. 



( = Corixa and Glaenocorisa in Saunders, I.e., = Basileocorixa 



Kirkaldy, olim.) 



Species 5. C. nigrolineata Fieber (fig. 18). 

 {■= fahricii in Saunders, I.e.) 



Palae, S, widely cultrate, broadest near the middle, one long 

 row of pegs, the basal twenty of which are pegtop-shaped, the 

 apical nine more elongate. They follow more or less the upper 

 curve of the pala. 



NigTolinmta smd fahricii are certainly only unimportant colour- 

 varieties of the same species. 



Species 6. C. saundersi Kii-kaldy, 1899 (Fig. 17.) 

 Palae cultrate, the upper margin arcuate, not produced back- 

 wards ; base rather broader than the apex of tibia ; one row of 

 about twenty blunt, rounded pegs, the last six more elongate. 



This very distinct little species is known only from four 

 specimens (3 (^ ^ 1 ?) collected in June 1873 at Ohobham, 

 Surrey, by Mr. Saunders. I visited the pond in which it was 

 captured eleven times altogether during 1899 and 1900, many 



