19060 OO 



SYNOPTIC TABLE OF BRITISH NEMATUS spp. 



1. Wings infuscated with black, tliorax (including pronotunn) black in both sexes, 



abdonieii reddisli-orange, $ saw-shoath (viewed from above) extremely broad 

 right up to the apex, which is Lruncately rounded ahdominalis, Pz. 



— Wings yellowish or hyaline ; pronotum more or less marked with yellow ...2. 



2. Abdon)en above more or less streaked transversely with black. Saw-sheath of ? 



tapering from a broad base to a narrow apex (subtriangular, viewed from 

 above). Mesonotum of S black ; that of 9 generally entirely luteous, but 

 sometimes (? ^= calednnims, C.) with black markings... acwm'natMS, Thoms. 



— Abdomen not streaked with black. Saw-sheath of ? broad at the apex as in 



ahdominalis 3- 



3. Mesonotum in both sexes luteous, with a black longitudinal stripe on each lateral 



lobe h%lineatus,'K.\. 



— Mesonotum black in the <? , entirely luteous in the $ luteiis, F. 



Easilv as the above species can be separated by colour ebaracters, 

 the only important " structural " distinction among tbem seems to be 

 that between the triangular saw-sheatii of acmninatus and the sub- 

 quadrate ones of the other three species. Ahdominalis, lufeus, and 

 hiJineatus are all attached to the alder ; the first two often occurring 

 on it (in this neighbourhood) simultaneously and in great numbers. 

 Bilineatus I have never taken ; it is perhaps a more northern form. 

 Mr. Routledge has taken it near Carlisle. 



Acuminntus is attached, Mr. Cameron thinks, to the birch. All 

 my specimens of it were received from Mr. Thornley, taken on Ben 

 Nevis. Among them were ^ ^ , which sex Mr. Cameron says he does 

 not know. Occurring alone they might easily be passed over 'd^ S 6 

 of luteus, but the edges of the dorsal abdomiual segments are black as 

 in the $ ? . 



NOTE ON OTHER SUPPOSED BRITISH NEMATUS spp. 

 In Cam. Mon., vol. iv, three more species are enumerated as be- 

 longing to Nematus in Kouow's sense. These are — 



1. Caledonicus (described in vol. ii, p. 159). 



2. Aurantiacus (described as antennatus in vol. ii, p. 155, not 



identical with the species descrrbed in vol. ii, p. 173, as 

 aurantiacus) . 



3. V-flavum (described in vol. ii, p. 142). 



1. — Caledonicicfi, from the description, appears to me to be only a 

 form of acuminatus, ? , which has been sent to me along with normal 

 ^ ^ and 2 ? of the same species by the Rev. A. Thornley, taken 

 with them on Ben Nevis. 



