24 B. C. ENTOMOLOGICAL SOCIETY 



margins gently curved, rather broadly flattened and a little reflexed 

 anteriorly ; veins feebly elevated, the interior forked, with branches 

 reaching membranal suture. Membrane with four areoles, the inner 

 longest, extending anteriorly about one-eighth of its length beyond base 

 of the next and posteriorly almost as far as the next ; outer margin 

 thickened, pubescent. Second segment of hind tarsi about as long as 

 the third. Last ventral segment of female more than twice as broad as 

 long (40-15), somewhat produced and broadly rounded at middle. 

 Form rather elongate oval. Length male and female, 5-5.5 mm ; width 

 2.3-2.5 mm. 



Holotype, female, Duncan, B. C, 17-IX-'19 (W.D.), in the National 

 Collection at Ottawa. 



Allotype, male, same data, in Downes' collection. 

 Paratypes, male and female, in my collection. 



This species may be recognized by its narrow form and its dull 

 black colour, with inconspicuous spotting; it is distinguished from 

 interstitialis and allied species also by the strong transverse carina 

 separating frons and tylus, which is very distinct at middle as well as at 

 the sides. According to my interpretation of Reuter's essay^^ at the 

 generic subdivision of Salda (or Acanthia), this form pertains to Saldula 

 Van D. (Acanthia Reut.). I am not fully satisfied that many of the 

 characters which Reuter employs are really of generic value, and some 

 of them are certainly indefinite, e.g., the relative width of head and 

 anterior margin of pronotum and the punctation of the transverse pro- 

 notal impression. This latter character is mentioned in the above 

 descriptions and it is present in allied species, although they belong to 

 a group which, according to Reuter, lacks this feature. Probably the 

 punctures are merely developed in varying degrees in the different 

 sections. The characters used by Reuter in separating his genera are 

 included in the present descriptions. 



Family NOTONECTIDAE 

 Notonecta undulata Say.* Vernon, 26-IX'19 (W.D.). 

 Buenoa elegans Fieber. Beaver Lake, Saanich Dist., 9-VIiri9 

 (W.D.). Study of a good series has revealed no differences between 

 specimens taken in the west and in the east. The proper application 

 of the names elegans and platycnemis of Fieber may be considered some- 

 what in doubt, but these specimens exhibit the characters ascribed to 

 elegans by Hussey {Op. cit., p. 18). 



"Zur gen. Teilung paL u. neark. Acanthiaden, Ofv. Finska Vet.-Soc. Forh., 

 LIV, Afd. A, No. 12:1-24, 1912. 



