Pfittella.] CT.AVICORNIA. ] 13 



Under bai-k of viifious dead trees, often in company with P. apfera,]ocii]]y cmn- 

 mou ; Sherwood Forest; Sutton near Birmingham; SoliliuU ; Salford I'riors; 

 Cannock Chase ; Windsor ; VVickeu Fen. 



P. tenella, Er, (1 m'tcroscopica, Waltl.) Elongate, very iianow, 

 pale yellow, clothed with short pale hairs ; liead large, elongate in front, 

 eyes (at all events in the female) very large, antennas rather long, ])alo 

 3'cllow ; thorax very short, much shorter than head, with sides roundeil 

 in front, and strongly constricted behind, posterior angles prominent, 

 very acute, extremely finely tuberculate ; elytra long and narrow, much 

 longer than head and thorax, with sides scarcely rounded, very finely 

 asperate in remote transverse roAvs, apices strongly rounded, with a lon- 

 gitudinal hand of darker colour in the female : logs rather long, pidc 

 yellow. L. | mm. 



Very rare ; one example has been takiMi by Mrs. Matthews under bark of dead oalc 

 in Sla-rwood Forest ; it is very rare on tlie Continent. 



The species may be known by its very short thorax, which is strongly 

 constricted behind, long elytra, and firie sculpture, 



TRZCHOFTBZt^X, Kirby. 



This genus contains a very large nvimber of species ; seventy- four are 

 enumerated by Mr. Matthews in his monograph, but a considerable number 

 have since been described from Central America and other parts of the 

 world, and the genus is so widely distributed that it is probable that only a 

 small fraction of the existing species are at present known, as very few col- 

 lectors trouble themselves to look for them ; they are distinguished by not 

 having the thorax constricted behind and by the fact that the abdomen 

 has six free ventral segments ; they are very rapid in their movements and 

 run with a swift jerky motion very different from that of 'Ptenidhim, and 

 Pttlium; there are thirty-nine Iiritish species at present known^ which in 

 many instances are exceedingly closely allied, and require the greatest care 

 in their determination ; they may be roughly divided as follows, but, as 

 above stated, no really satisfactory table can be formed ; the colour, for 

 instance, is in many cases a very important point, but immature 

 specimens of the black species are sometimes reddish or brownish ; 

 Mr. Matthews and I once found a large number of a brownish-looking 

 Tndwpteryx in faggots in Sherwood Forest, which we thought at first 

 must be a good species, but they turned out to be very sliglitly 

 immature T. fascicular is ; the only way to work the genus is first to 

 separate those that seem at all diiferently formed by a simple Codding- 

 ton or Browning's platyscopic lens, and then to compare ihem caivfuUy 

 with authentic specimens of the species to which they seem to belong 

 under a compound microscope, with a rotating stage, as the asperate 

 sculpture presents a very different nppearance in different lights. 



The species are chiefly found in hot-beds, haystack refuse, dead leaves, 

 VOL. iir. I 



