Bembidium.] adephaga. 101 



vei'3' closely one into the other, and make the study of the group difficult 

 unless they are more or less classed together, in which case they become 

 a help instead of a hindrance. One of the most distinct of these suh-genera 

 appears to be the genus Bracfeon, Bedel, which has only recently been 

 founded to include B. jJCtludoauvi. and its allies. 



Thomson (Skand. Col. i. 196) describes a larva which he found 

 living in company with B. ustnlatnm, and which he considers to belong 

 to that species ; it is yellowish, with head and thorax shining, of a liorny 

 consistence, abdominal segmeiits leathery ; head as long as broad, not 

 narrower than thorax; antenniB four-joiiited ; maudibles strong, sickle- 

 shaped, with a sharp tooth before middle ; thorax almost square as long 

 as the meso- and meta-thorax together; abdomen narrower than thorax, 

 last segment with two long, unjointed, uneven cerci furnished with 

 several outstanding bristles ; legs rather short, tarsi with single claws. 



The larva of JB. bipunctatum, L., is fij^ured by Schiodte, iii., PI. xx., Fig'. 17, and 

 agrees with Tlionisoii's description of the larvii of 5. tw^«^«/«m in lUiiiiy points : 

 the head is strongly sulcate, and the clypcus serrate ; the protliorax is siihquadrate, 

 rather transverse, with all the angles rounded; the cerci are about half as long again 

 as the cylindrical anal appendage, and are curved inwards so that they almost meet at 

 their extremity ; the abdominal shields are not margined, and the muscular impres- 

 sions are obsolete ; the legs are rather short with single solid claws. The larva of 

 B. j)alUdipenne ditiers from the two preceding by its much paler colour. 



As there are nearly tifty species of this genus found in Britain 

 (i;pwards of a sixth of the whole of the Carabidaj found in the country), 

 and as they are mostly of very small size and many of them run very 

 closely one into, the other, tliey generally alibrd great difficulty to 

 stutlents : besides the usual tables, I have therefore added a summary 

 depending entirely on colour, without reference to other distinctions, as 

 a help to beginners, and I hope that the difficulties may thus be in some 

 degree lessened. 



I. Anterior margin of thorax abuost straight ; apex of metasternum bordered between 

 intermediate coxaj. 

 i, Stiiie of elytra much feebler at sides,, often evanescent, seventh stria at least 

 almost always effaced behind or absent. 



1. Thorax not cordiform, with sides rounded regulai-ly from apex to posterior 



angles. 



A. Posterior angles of thorax with a depression not bounded by a longitudinal 

 fold; third interstice of elytra with one piliferous pore behind middle; 

 auteuna3 red. 



Group L (Ocys, Stcpli.) 



B. rufescens, quinquestriatum. 



B. Posterior angles of thorax with a deep depression bounded by a longitudinal 

 fold; third interstice of elytra with two piliferous pores; anteiintB 

 brownish with lighter base. 



Group II. (Philoctlius, Steph.) 



B. ohtusum, biguttatum, riparium, aneum, gultula, Munnerheimi. 



2. Thora.\ narrowed behind, strongly cordiform, posterior angles acute. 



