70 THE FAUNA OF SCOTLAND. 



21 (22) Reddish-yellow ; antennae thick, third joint longer than fourth^ 



strongly emarginated; mesonotum shining; claws simple; 

 abdomen scarcely petiolated, - - - - Biorhiza. 



22 (21) Mesonotum not reddish-yellow; the antennae thin, the third 



joint emarginated; abdomen petiolated; claws bifid, 



Dryoj)hanta, 



Ohs. — Cymps has no known male. 



SYNOPSIS OF THE SCOTTISH OAK GALLS. 



1 (19) Situated on the underside of the leaves. 



2 (7) Round, soft and succulent, often with rosy cheeks. 



3 (6) Appearing in the spring or early summer; diameter not more 



than 6 mm.; green. 



4 (5) Smooth, glabrous, - - Neiiroterus (SpatTiogastcr) laccarum, 



5 (4) Covered with long white hairs, Neiiroterus (tricolor) fumipennis. 



6 (3) Appearing in the autumn, yellowish-green; diameter 8 to 12 



mm., DryopJiantafoUL 



7 (8) Oval or ovoid, smooth, glabrous, pallid green or yellow, or 



brownish yellow, spotted with pink dots; moderately hard, 

 situated between two brownish sheaths, which remain after 

 the gall has fallen; length, 1.5-2.5 mm. ; in August and 

 September, Amlricus ostreus, 



8 (9) Reniform, small, green, succulent, crowded usually together ; 



September and October; length, 1-2 mm., 



Tn'gouaq)is (rcnum) mcyaptera. 



9 (12) Semi-spherical, depressed at top and bottom, hard and woody ; 



in autumn. 



10 (11) Whitish-yellow, sometimes with red bands, or with the sides 

 red ; the skin rough, with projecting points ; length, 5-7 mm,, 



Dryoplianta loiKjiventris. 



