THE CANADIAN ENTOMOLOGIST. 117 



head, posterior angles of eyes, and posterior margin of thorax 

 fuscous. Anterior margin of thorax and inner edge of wing pads 

 with rather dense brownish-black hairs. These together with the 

 pigmented posterior margin of the thorax form a square ; a median 

 patch of brown hair joining the band on the anterior margin. 

 General surface of thorax smoky brown with narrow median clear 

 line, and a paler transverse band in the middle. Head pale brown 

 with a darker shading on vertex. Whole dorsal surface of thorax 

 and abdomen sparsely hairy, the abdominal segments faintly indi- 

 cated by transverse brown stripes. A median longitudinal white 

 stripe }i the body-width in diameter runs the length of the dorsal 

 surface of the abdomen. Within this is a series of large pale brown 

 blotches, one on each segment, the third and fourth of these with a 

 distinct crescent of chestnut brown,^ marginal third of abdomen 

 smoky, fringed with cilia, but these less conspicuous because of the 

 general hairiness of the body. The wing-pads hardly extend beyond 

 the thorax. 



Tarsi all one-jointed. Firsf legs as before. Second leg with 

 femur as long as width of head, equal to tibia and tarsus together. 

 Claws 1/5 longer than tarsus. Third leg with tarsus equal to width 

 of head, feathered with dense hairs. Antennae ^2 the length of 

 tarsus of first leg. Interorbital space -/i the width of head, .and 

 equal to ^ the length from vertex to tip of beak. 



Fifth Instar. (Fig. 4). 

 Length -^^.Z mm. Width 1.4 mm. Dorsal marking as in previous 

 instar, but more intensified. The two median dark brown marks of 

 third and fourth abdominal terga oblong surrounded by a larger 

 oblong of smoky brown. Hairy covering of wing-pads and thorax 

 conspicuous, the median patch of the anterior border extending more 



8. These conspicuous markings are found on the dorsal surface of older 

 nymphs of all species of Corixids that I have examined. I have considered 

 them of glandular nattre, and they are so considered by Kunckel 

 d'Herculais (Comptes Rendus, cxx, p. 1,002, 1895), who remarks that the 

 dorsal position of the "scent glands" differentiates the Corixids from Nepa 

 and Notonecta, and put them phylogenetically nearer the Cimicids. J. 

 Guide, however, in an elaborate monograph published later ("Die Dorsal- 

 drii^en der Larv^en der Hemiptera Heteroptera" Ber. Senckenb. Ges., 

 1902, p. 85-136), describes the dorsal glands in all the various families of 

 Rhynchota, including the aquatic families, and denies the presence of such 

 glan s in any waterbugs. The Corixids examined were Corixa geofiroyi 

 (Leach), Arctocorisa linnei (Fieb.) and Cymatia coleoptrata (L,). He claims 

 that the conspicuous markings are merely the site of the insertion of 

 certain abdominal mascles. It would seem worth while to investigate 

 the matter further. 



