British Braconidx. 77 



■viewed sideways clavate ; 1st segment very narrow, cylindric, with 

 the tnbercles nearly in the middle ; 2nd one half longer than the 

 1st, narrow, subcylindric ; the following segments shorter, narrow 

 on the dorsum, widened and compressed laterally. Terebra in 

 repose not exceeding the tip of the abdomen ; when exserted, it is 

 as long as the 3 or 4 apical segments, slightly curved upwards, 

 acute, with the valves flattened, spathulate. The ^ is known by its 

 longer antennse, by the somewhat prominent sheath of the sexual 

 organ, and a lateral emargination of the 3rd segment, more strongly 

 marked than in the $ . 



The singularity of the neuration is explained by the dis- 

 placement of the cubital nervure, which instead of starting 

 from the prsebrachial transverse (as in other Hymenoptera) 

 originates at the flexure of the radial, causing there- 

 by some derangement of the rest of the system. Giraud 

 describes the head as "petite," by an evident lapsus 

 calami ; it is on the contrary remarkably large. Forster 

 has made a separate genus Eurypterna for the second 

 European species P. crcmieri, De Romand ; it is founded 

 on the different length, in the two species, of the isthmus 

 connecting the cubital areolets ; other differences there 

 are none. Fallen's genus Hyhrizon, published in 1813, 

 ought to take precedence of Pachylomma, if it were 

 adequately described ; but the definition is so loose that, 

 as remarked by Nees, it includes a number of other 

 insects, and even the whole tribe of Aphidians. Curtis 

 was the first to notice in Great Britain the species about 

 to be described ; he established in 1833 the genus Plancus 

 for its reception. 



Pachylomma Jntccata, De Brebisson. 



Paxylomma buccata, De Breb., loc. cit. 



Hyhrizon latehricola, Nees, Mon., i, 28, $. 



Plancus apicalis, Curt., Ent. Mag., i, Charactt. of undescr. 



Gen. and Spp. etc. $. 

 P. huccata, Ratz., Ichn. d. Forst., ii. 53, pi. ii, fig. 23 



(wing) ; Wesm., Nouv. Mem. Ac. Brux. 1835, p. 



90, $, pi. ii, (wing) ; Marsh., Species des Hym. 



d'Eur. et d'Alg. Bracon., vol. ii. p. 623, $ $, pi. xix, 



fig. 8 ; Giraud. Verb. d. zool.-bot. Vereins in Wien, 



1857, p. 11. 

 5 Black, or piceous in various degrees ; base of antennae, ab- 

 dominal sutures, and legs, testaceous. Head black ; clypeus, palpi, 



