TEIG.ONASPIS MEGAPTEEA. 115 



thorax united, smooth, shining ; with the $ petiolate. Wings large, 

 the radial cellule elongate, open ; areolet distinct. Head and thorax 

 black ; abdomen reddish-yellow. 



The wingless agamic form can only be confounded 

 with Biorhiza, which is much larger than it, has a 

 carina between the antennas, the head dilated more 

 behind the eyes, the ventral spine only 1 to 1 J times 

 longer than wide, and the parapsidal keels complete. 



The sexual form is easily known by the reddish- 

 yellow abdomen and large wings. 



There are only two European species known, and 

 the sexual form is one of the best marked in the whole 

 family. 



1. TeIGONASPIS MEGAPTEEA. 



PI. I, fig. 4 (megaptera, renum) ; PL XV, fig. 7 

 {megaptera). 



Cynips megaptera, Pz., F. G., Heft 79, 7. 



Trigonaspis crustalis, Htg., Germs. Zeits., ii, 195 ; Adler, Zeits. 

 wiss. Zool., xxxi, 198, pi. xi, fig. 18 a; 

 Licht., Oyn., 62, pi. ii, fig. 18 a. 

 — megaptera, Marshall, E. M. M., iv, 272; Mayr, 



Europ. Oyn., 31. 

 Cynips crustalis, Thorns., Opusc, 782, 4. 



Biorhiza renum, Giraud, Verh. z.-b. ges. Wien, 1859, 362 ; 

 Adler, Zeits. wiss. Zool., xxxi, 197, pi. xi, 

 fig. 18 ; Licht., Oyn., 61, pi. ii, fig. 18. 

 Trigonaspis renum, Mayr, Europ. Cyn., 31. 



Agamic Form. — Apterous, yellowish-red, the abdomen darker, with the 

 legs paler than the body ; thora,x punctured, opaque, abdomen shining ; 

 the vertex finely shagreened. Antenna 13-jointed, the last joint twice 

 the length of the penultimate ; claws simple, dilated at the base. 



Length 1*5 mm. 



The only other European species is B. synaspis, 

 Htg., which may be known from ours by the claws 

 being cleft, and by the antennae having 14 joints. 



Gall. — Small, 1 — 2 mm., irregularly kidney-shaped, 

 greenish yellow, sometimes reddish ; soft, succulent, 

 usually crowded together along the nervures. Length 

 2 to 3 mm. Found in the autumn, falling when 



