THE WELSHMAN'S BUTTON 49 



Family . . SERICOSTOMATID.E 

 Genus . . Sericostoma 

 Species . . personatum 

 Spurs, 2.2.4. 



PLATE X 



Sericostoma personatum is known in Hamp- 

 shire as the Welshman's button, and is one 

 of the day -flying sedges. As a general rule it 

 appears in such abundance as to prove a worthy 

 substitute for the mayfly where this insect has 

 become too scarce to bring the big fish up to 

 feed. The reddish -mahogany colour observed 

 when the insect " hatches " up through the 

 water and flops about on the surface, rapidly 

 darkens with age and exposure to light and air, 

 and the flies seen on the grass and sedges are 

 usually of a deep chest nut -brown. The female 

 is variable in its coloration, and frequently 

 exhibits white patches on the wings. These 

 patches are so uniform where they occur at all 

 that McLachlan has classified the flies bearing 

 them as varieties. Sericostoma multiguttatum varieties. 

 he describes as being variegated with hoary 

 pubescence which in S. analis is almost reduced 

 to a triangular spot at the termination of the 

 seventh apical sector. 



It should be observed that these variations 

 only occur in the female sex. 



The abnormal maxillary palpi of the male 



