38 MAXDIBULATA. HYMENOPTEEA. 



The male has some black spots on the testaceous segments of the abdomer?. 



More abundant than the last ; found in the vicinity of London, at 

 Coombe and Darenth woods, and also at Dover in the beginning of 

 June. 



Sp. 45. vicinus. Niger, mandibulis apice palplsque piceo-nigris, pedibus testaceis, 

 femoribus basi infumatis, tibiis 2-bus posticis apice tarsisguefuscis. (Long. 

 Corp. 4.|— 5i lin.; Exp. Alar. 7§— 9| lin.) 



Ne. vicinus. St. Fargeau. — Steph. Nomen. 2d edit. col. 125. — Ne. consobrinus. 

 Steph. CataL 329. No. 3820. 



Head and antennae black ; mandibles at the apex and the palpi pitchy-black ; 

 thorax and abdomen black ; legs testaceous, with the base of the femora 

 sometimes dusky, or black, the 2 hinder tibise at the apex, which is slightly 

 dilated, and the tarsi fuscous ; wings hyaline, with the costa and nervures 

 at the base testaceous, brown at the tip. 



The basal joint of the hinder tarsi is slightly dilated in this species. 

 Rare : taken occasionally at Darenth wood, in June. 



Genus XIII.— CRCESUS, Leach. 



Aniennw 9-jointed, simple in both sexes, slightly pilose in the males, basal 

 joint short, 2nd shorter, 3rd longest, the remainder gradually decreasing in 

 length to the apex, which is attenuated : mandibles unidentate : labrum 

 rounded : head broad : ocelli 3 : abdomen cylindric in the males ; broader 

 and somewhat carinated in the females: icings ample; anterior with I 

 marginal, and 4 submarginal areolets, the Jst small, subquadrate, 2nd 

 large, elongate, receiving 2 recurrent nervures, 3rd small, quadrate, 4th 

 extending to the apex : 4 anterior legs simple ; posterior rather stout, their 

 tibise dilated at the apex; tarsi with the basal joint longest, considerably 

 dilated and compressed, remaining joints small, simple. 

 Exclusively of other less conspicuous differences, Croesus differs 

 from Nematus in having the hinder tibiae and the basal joint of the 

 hinder tarsi considerably dilated and compressed, a structure that 

 partially obtains in Ne. vicinus, but that insect is sufficiently removed 

 by its general habit ; and as there are evidently several good species 

 of Croesus, it ought clearly to be considered as distinct from Nematus, 

 intervening forms, as elsewhere pointed out, not alone being suf- 

 ficient to unite discordant genera. 



Sp. 1. septentrionalis. Niger, palpis piceis, abdominis medio tibiisque ante- 

 rioribus ferrugineis, alis hyalinis pone medium, subinfuscatis. (Long. corp. 

 4— 4J lin. ; Exp. Alar. 9— 9§ lin.) 



Te. septentrionalis. Linne.—Cr. septentrionalis. Steph. Catal. 330. iVo. 3821. 



Black: palpi pitchy ; abdomen with the 3rd to the 6th segments ferruginous, 

 and in the females a spot on the 7th; anterior legs black at the base, the 



