DONISTHORPEA. 233 



On July 22nd, 1911, I dug up a nest of D. aliena at Weybridge 

 which contained plenty of workers and small cocoons, some males, 

 and a number of umbrata workers 57 , and on July 12th, 1913, I dug 

 up a mixed colony of umbrata and aliena situated in a sandy bank, 

 also at Weybridge, when both species picked up and carried off the 

 small cocoons exposed by excavating. These two observations and 

 the last two experiments show that D. aliena may also act as the 

 host of D. umbrata females, and as aliena is not nearly so pug- 

 nacious an ant as nigra, the females may more easily accomplish 

 their object. 



The following myrmecophiles have been taken with Donisthorpea 

 umbrata in Britain : 



Coleoptera : Myrmedonia humeralis Gr., and Homalota con- 

 sanguinea Epp. 



Formicidae : Stenamma westwoodi West. 



Diptera : Pseudacteon (=Phora) formicarum Verrall. 



Aphidae : For da formicaria HeycL, Tycheoides setariae Pass., and 

 Geoica formicina Buckton. 



Collembola : Cyphodeirus ( = Beckia) albinos Nic. 



Araneina : Cryphoeca recisa Camb. 



Acarina : Cillibano comata Leon., Urodiscella philoctena Trouess., 

 Uroplitella minutissima Berl., Uropoda ovalis Kram., Trachyuropoda 

 wasmanniana Berl., T. bostocki Mich., Antennophorus uhlmanni 

 Hall., Laelaps cuneifer Mich., Sphaerolaelaps holothyroides Leon, and 

 Tryoglyphus wasmanni Mon. 



Crustacea : Platyarthrus hoffmanseggi Brdt. 



Donisthorpea umbrata Nyl., var. mixto-umbrata For. 



Lasius umbratus mixto-umbratus Forel Denkschr. Schweiz. Ges. Naturw. 

 26 48 (1874) 1 . Lasius mixto-umbratus Andre Spec. Hym. Europe 2 196 

 (1881) 2 . Lasius umbratus var. mixto-umbratus Dalla Torre Cat. Hym. 7 

 192 (1893) 3 . Lasius umbratus Farren- White Ants' Ways 84-85 (1895) 4 (in 

 part). Lasius umbratus var. mixto-umbratus Donisthorpe Ent. Rec. 25 

 04 5 96 6 (1913). 



Original description of L. mixto-umbratus Forel : 



" Pilosite intermediate entre celle des deux races. Je n'ai pas encore 

 trouve d'autres fourmilieres formant transition entre ces races, vu leur 

 rarete et leur vie cachee (seulement des $ isolees) ; mais leurs caracteres dis- 

 tinctifs sont si peu solides, leurs moeurs, leur habitus, leur taille si identiques 

 que je ne doute pas que ces transitions n'existent." 1 



Wasmann points out that " Between L. umbratus and mixtus 

 intermediate varieties are more common than the pure race forms " 

 [Archiv. Trim. Inst. Grand Ducal Luxemburg 1 11 (1906)]. 



This variety embraces forms which are intermediate between 

 umbrata and mixta in size, colour, hairiness, and pubescence of 

 the body and legs, etc. ; it may be due in part to hybridism, and is 



