1918.] 57 



the're is any reason for assuming that the laws of heredity are suspended 

 in the case of Notonecta ; and there is no advantage in continuing to 

 attribute to JS . glauca a degree of variability that it does not possess, 

 simply in deference to the opinion of any authorit}^ however eminent, 

 which there is no evidence to support. 



These insects are so common that if furcata and maculata are 

 the oii'spring of glauca, there ought to be no lack of intermediate 

 specimens indicating the fact ; but Kirkaldy, the reviser of the genus 

 (Trans. Ent. Soc. Lond. 1897, pp. 397 et seq.), who may fairly be 

 assumed to have had access to abundant and varied material, could find 

 no intermediates between glauca and furcata from localities nearer 

 than Persia and Kashmir. The only named form which appears to be 

 a variety of glauca is marmorea Fab. as defined by Kirkaldy, which 

 has the metanotiim black, yellow-brown elytra with darker mottling, 

 and the connexivum greenish-testaceous. According to Kirkaldy this 

 variety has been confused with maculata Fab., and as regards the elytral 

 pattern and colour some forms of marmorea and maculata are quite 

 indistinguishable. Even so the latter may be known by its orange- 

 yellow metanotum ; but marmorea would only be separable from 

 specimens of glauca with an excess of dark mottling on the elytra 

 by the greenish-testaceous connexivum. Kirkaldy gives the connexivum 

 of glauca as black, but I have invariably found it dull ochi'eous with 

 the junction of the segments brown, as described by Douglas & Scott 

 (Brit. Hem. p. 588). I have not seen any form of glauca to which the 

 name marmorea could be applied, though it is evidently the insect 

 referred to by Dale, as quoted by Douglas & Scott {t. c. p. 589) in the 

 following passage: — "Some varieties of N. glauca, with the wings 

 closed, do not show any great variation from N. maculata ; . . . ". 

 Kuhlgatz (in Brauer, Siisswasserfauna Deutsclilands, Heft 7, p. 81, 

 1909) uses the name marmorea Fab. for the insect which is here called 

 maculata Fab. ; but I adopt the view of Oshanin (Verz. Pal. Hem. i, 

 p. 975), who regards as representing N. maculata Fab. the figure of 

 Herrich-Schaffer (Wanz. Ins. viii. p. 23, fig. 797), which, teste Douglas 

 & Scott, I. c, is a copy of that of Curtis (Brit. Ent. t. 10) and therefore 

 represents our insect. 



I am indebted to my esteemed colleague, Mr. E. A. Butler, for the 

 opportunity of characterizing an additional native species of this genus 

 which he found at Whitstable in April, 1912, associated with Coelam- 

 bus parallelogrammus, and at Kye in March, 1913, in company with 

 Corixa selecta. An example of this insect was sent some time since to 

 Dr. Horvath, who could see in it nothing more than another variety of 

 N. glauca. 



