FORMICA. 295 



male on right, worker on left, the line of division not being quite straight 

 however, the black colour on the right side of the mesonotum encroaching 

 on the red colour of the left side. Petiole divided sharply, black on right, 

 red on left side. Gaster black, the right half with male pilosity and sculp- 

 ture, left half worker. External male genitalia are present on the right side, 

 the anal sternite being present only on that side. The red and black colour 

 is sharply denned beneath, but the coxae are all black and red as in the male, 

 and the legs on both sides are somewhat infuscate, the tarsi on the right side 

 being longer. Winged of course only on right side, the veins and stigma are 

 pale, and more like those of the female. Long. 7 mm." 64 



" Lateral gynandromorph ; male on left side, female on right. Both 

 antennae female, head somewhat small, but female shape, left eye a little 

 larger than right, ocelli female. Head black, with exception of clypeus and 

 right mandible, which are red ; greater part of thorax red and black, evenly 

 divided laterally, only the top right corner of the epinotum being red. A 

 bit of the scutellum and post-scutellum on the left side where the wing is 

 joined, red. Petiole sharply divided, red on right side, black on left. Gaster 

 black, the right side with female pilosity and sculpture, left side with that of 

 male. Colour sharply denned underneath. Legs and coxae female on right 

 side, male on left. External male genitalia are present on left-hand side. 

 Fully winged on both sides, the stigma and veins being darker, as in the 

 male. Long. 9 mm." 04 



Andre gives June and July for the marriage flight of sanguined 28 , 

 and Schenck July 11 , while Smith suggests August 17 . Forel saw the 

 males and winged females leaving a nest at Vaux from seven to 

 eight o'clock in the morning on July 3rd, 1873 25 ; I have found 

 winged females away from their nests at Bewdley on July 20th, 

 1909. 



Pseudogynes of sanguined have been observed in numbers, and 

 Wasmann attributes the occurrence of these entirely to the presence 

 of the beetle Lomechusa strumosd in their nests. 



I shall not discuss the subject fully now, hoping to deal with it 

 at length on a future occasion, and shall therefore only give the 

 results which Wasmann deduces from his observations on the 

 occurrence of these forms, and my own experience, such as it is, 

 with these curious individuals. He has studied and described 

 numerous forms of them, in Holland and in Luxemburg, and he 

 says : 



(a) The pseudogyne district always coincides with the Lome- 

 chusa district. 



(b) The pseudogyne-holding colonies are always the centre of 

 the Lomechusa district. 



(c) Outside the Lomechusa district pseudogynes are never 

 found in sanguinea colonies. 



(d) In colonies where Lomechusa only dwells as an imago, 

 pseudogynes are not produced, but rather only in those in which 

 Lomechusa has brought up its larvae for many years 49 . 



On May 22nd, 1908, I found pseudogynes in plenty in a colony 

 of F. sanguinea in the New Forest, but after having dug up the 



