16 MONOGRAPHIA CHALCIDUM. 



Sp. 5. Isos. simile. Mas. N/grum, prcecedentihu/! (wgusiius, 

 jjrothorace antict macalis duahus obscure jiav'is, alls 

 fuscis. 



Caput obscurum : thorax punctatus, maculis antice duabus lateralibus 

 obscure flavis : petiolus obscuras, punctatus : abdomen nitidum, 

 glabrum : antennae basi flavas : tibiae nigro-fuscse, anticas apice 

 flavae : tarsi fusci : genua flava : alae fuscescentes. (Alarum 

 longitudo, If lin.) 



It is nearly allied to Isos. longulum, but is much smaller, and 

 appears later in the year : the body is more slender : the wings 

 narrower and darker. 



July ; amongst grass in fields ; Southgate. 



Sp. 6. Isos. angustipenne. Mas. Nigrum, prothorace antice 

 macidis duabus pallide Jlavis, alls fuscis angustis. 



Caput obscurum : thorax punctatus, maculis antice duabus late- 

 ralibus pallide flavis : abdomen nitidum, glabrum : antennae basi 

 tarsique fusci : genua flava : alas fuscae. (Alarum longitudo, 

 n lin.) 



The wings of this species are very narrow, their breadth 

 not being more than one-fourth of their length ; this character, 

 and its fuscous wings, will distinguish it from most species of 

 Isosoma. 



May; amongst grass in moist situations; Southgate. 



Sp. 7. Isos. brevicorne. Mas. Nigrum, prothorace antice 

 maculis duabus albidis, antennis dimidio corporis vix lon- 

 gioribus, alis fuscis. 



Caput obscurum : thorax punctatus, maculis antice duabus latera- 

 libus albidis : petiolus obscurus, punctatus : abdomen nitidum, 

 glabrum : antennae quam in praecedentibus breviores : tibiae 

 anticse fuscae, subtus flavae : tarsi flavi, articulis 4 et 5 fuscis : 

 genua flava : alae fuscae. (Alarum longitudo, \\ lin.) 



This species is more minutely punctured than any of the 

 preceding : the sides of the proscutellum have each an obscure 

 white spot on their anterior margins : the antennae are very 

 short, scarcely more than half the length of the body : the 

 three basal joints of the tarsi are yellow, the fourth and fifth 

 fuscous : it resembles Isos. crassicorne, of which, possibly, it 

 may be the male, but it is much narrower, the antennae are 



