77« M. W. R. de V. GRAHAM 



wrong data, agrees remarkably well with the original description of cychreus and in 

 my opinion indicates that cychreus must have been the male of Gyrinophagus aper 

 (Walker). It is a Haliday specimen, labelled in his handwriting " Waterside 

 Glassnevin [sic] 49.8.2 " and [a modern printed label] " Ireland. Haliday ". The 

 locality mentioned (Glasnevin) contains the Botanical Gardens and is a suburb of 

 Dublin, not so far from the original locality, Phoenix Park (Walker, 1850 : 132 

 " Found on the edge of a pond in the Zoological Gardens, Phoenix Park in 

 September "). 



Isocyrtus marginatus Thomson. Syntypes, 8 specimens. LECTOTYPE, a male 

 labelled " Wll [?] 7/69 " and " marginatus Ths ". 



Britain, Ireland, Sweden. 



Biology. Reared from cocoons of Sisyra fuscata (F.) at Oxford, 24. v. 1932 

 (F. J. Killington). Imagines May-Sept. 



Gyrinophagus luteipes Ruschka 



Gyrinophagus luteipes Ruschka, 1914 : (209), <$ $. 



Gyrinophagus luteipes Ruschka ; Delucchi, 19556 : 153, fig- 7, E, F., <$ $. 



Type material. Syntypes, Germany, Westphalia, Munster, 3 $ and 1 J, reared 

 from pupal cocoons of Gyrinus natator L., in coll. Ruschka, Naturhistorisches 

 Museum, Vienna ; re-examined by Delucchi. 



According to Delucchi (1955&) the types of luteipes are very close to marginatus 

 [=aper) but differ in being smaller ($ 17 mm., $ 1-4 mm.) ; the female has all the 

 funicular segments of the antenna slightly transverse, the first segment shorter than 

 the sixth, and the sensilla sparser ; the male has smaller eyes and uniformly yellow 

 antennae ; the basal cell and costal cell of the fore wing are relatively less thickly 

 haired. Excepting the colour of the antennae, the above differences are such as 

 one might expect if the types of luteipes were just unusually small examples of aper. 

 The range of variation in size of the available specimens which I regard as belonging 

 definitely to aper is 2-0-2-8 mm. for females, 1-7-2-7 mm. for males. The sizes 

 given by Delucchi for the two sexes of luteipes fall outside this range, so that there 

 is some room for doubt. Further study is necessary to settle the problem. 



Note. Gyrinophagus splendens Erdos (1957 : 64, fig. 7b-e, $ $) is probably not a 

 Gyrinophagus but a Eupteromalus ; Erdos states " coxis posticis nudis ", a character 

 which suggests the latter genus. 



Note. Sisyridivora Gahan (1951 : 100) must be near Gyrinophagus. It is said, 

 however, to have a large triangular hollow on the gena, extending to the lower edge 

 of the eye ; the female of Gyrinophagus lacks such a hollow, whilst the male has a 

 small one which does not extend to the eye. 



