

DONISTHORPEA. 187 



ceased to be used until 1861, when Mayr [Europ. Formicid. 49 

 (1861)] revived and re-characterized Lasius F., adopting niger 

 L., F., as his type. Bingham [Faun. Brit. India. Hym. 2 338 

 (1903)] and Wheeler [Ann. New York Acad. Sc. 21 165 (1911)] also 

 cite niger as the type. This species was also adopted as the Type 

 by Morice and Durrant [Trans. Ent. Soc. Lond. 1914 421-423 (1915)] 

 who gave the following reasons for the change of name : " In the 

 Systema Piezatorum Fabricius made use of Jurine's name Lasius, 

 but applied it to a genus of Ants which he separated from For- 

 mica L., and later authors have ignored Jurine's Lasius, no doubt 

 because the publication of the Piezatorum (1804) antedates that 

 of the Nouvelle Methode (1807). But the real date of Lasius Jrn., 

 as we now learn, is May 30th, 1801 (Erlangen List) Lasius F. 

 (1804) therefore sinks as a homonym of the earlier Lasius Jrn. A new 

 name for Lasius F. is necessary, there being apparently no exist- 

 ing synonym, we therefore propose that it be called Donisthorpea 

 in recognition of Mr. H. St. J. K. Donisthorpe's careful investiga- 

 tions into the bionomics of this and other Heterogynous genera." 



5 Head cordate ; clypeus broad, convex, rounded anteriorly, posterior 

 border distinct ; frontal carinae fairly short ; frontal area indistinctly defined, 

 broader than long, rounded posteriorly ; frontal furrow indistinct or some- 

 times distinct ; mandibles triangular, terminal border dentate ; maxillary 

 palpi six- join ted ; labial palpi four- jointed ; antennae twelve- join ted, 

 funiculus with joints two to five not longer than the succeeding ones ; ocelli 

 indistinct. Thorax short ; pronotum rounded, suture between pronotum 

 and mesonotum distinct ; mesonotum convex ; epinotum short, with a flat, 

 sloping surface posteriorly. Petiole with scale vertical, or slightly inclined 

 forward ; gaster oval, natter than in Formica. Legs shorter than in Formica. 



$ Head as in the ^ ; ocelli distinct. Thorax robust ; pronotum short ; 

 mesonotum large, rounded and convex anteriorly, flat posteriorly ; scutellum 

 broad, very slightly convex ; epinotum sloping, rounded posteriorly. Wings : 

 fore-wings with one cubital cell, and one discoidal cell, the latter sometimes 

 wanting. Gaster flatter than in Formica. Legs shorter than in Formica. 



$ Head triangular ; clypeus, frontal area and palpi as in the ; frontal 

 carina short, slightly divergent posteriorly ; mandibles broad armed with a 

 single tooth at apex, or with terminal border dentate ; antennae thirteen- 

 jointed, with the first joint of the funiculus broader, and the last joint longer 

 than the rest. Petiole, with scale as in the . External genital organs very 

 small. Wings as in the $. Size generally much smaller than in the $. 



Ovum : White, round oval. 



Larva : Pale yellowish white, long, very narrow, and curved anteriorly, 

 with the segments distinctly defined, and gradually increasing in breadth 

 till just before the base. The whole body covered with short, slightly curved, 

 yellow hairs of about equal length, which are more abundant in the younger 

 larvae. The body appears to be finely striate transversely. 



Pupa : Enclosed in pale reddish yellow cocoons, but sometimes naked. 



Original description of Lasius F. [Fabricius Syst. Piez. 415 

 (1804)] :- 



" Lasius Os absque lingua. 



Mandibula brevis, fornicata, apice rotundata cum acumine. 



Labium maxilla brevius. 



Antennae medio frontis insertae, fractae." 



