MONOGRAPHIA CllALCIDUM. 19 



by its narrower wings : the antennae are much shorter, the 

 wings shorter and narrower than those of Isos. longicorne. 

 July ; amongst grass in fields ; Southgate. 



Sp. 13. Isos. petiolata. Mas. Nigrum, 2:>rotliorace antke 



maculis duabus albidis, petiolo elongato, alls subfiiscis. 

 Caput obscurum : oculi rufo-fusci : ocelli rufi : thorax punctatus, 

 maculis antice duabus lateralibus albidis : petiolus obscurus, 

 punctatus, abdominis dimidio longior : abdomen nitidum, glabrum : 

 tarsi fusci : tibiae anticaj apice genuaque flavee : alae subfuscse. 

 (Alarum longitudo, l^lin.) 



The petiole in this species is much longer than in any of 

 the preceding, its length being more than half that of the 

 abdomen : the body is nearly double the length of the 

 antennae : the wings are slightly fuscous, the nervures 

 darker. 



July ; amongst grass in fields ; Southgate. 



Sp. 14. Isos. cornutum. Mas. Nigrum, prothorace antice 

 maculis duabus pallide Jlavescentibus, alis hyalinis. 



Caput obscurum : oculi rufo-fusci : ocelli rufi : thorax punctatus, 

 maculis antice duabus lateralibus pallide flavis : petiolus obscurus, 

 punctatus, abdominis dimidio longior : abdomen nitidum, glabrum : 

 tibiae apice, genua tarsique flavi ; coxae tarsique apice fusci : 

 tibiae anticae fuscae, subtus flavaj : alae hyalinae, nervis pallide 

 fuscis. (Alarum longitudo, 1^ lin.) 

 This species resembles the preceding in shape : it is 



smaller: the wings are hyaline, the nervures pale yellowish 



fuscous, and the stigmal branch forms a more acute angle with 



the superior margin of the wing. 

 September ; Isle of Wight. 



Sp. 15. Isos. tenuicorne. Mas. Nigrum, prothorace antice 

 maculis duabus albidis, antennis gracilibus, alis subhi/alinis. 



Caput obscurum : oculi ocellique rufi : thorax punctatus, maculis 

 antice duabus lateralibus albidis : petiolus obscurus, punctatus : 

 abdomen nitidum, glabrum : tibiae anticae nigro-fuscae : genua 

 flava : tarsi fusci : alae subhyalinae, nervis pallide fuscis. (Alarum 

 longitudo, 1 lin.) 

 It has much resemblance in form to Isos. elongatum : it is 



narrower in proportion, and smaller : the antennae and wings 



are more slender. 



May ; grass in fields ; Southgate. 



