114 [March, 



of great iniportauce, although there appears to be eousiderable varia- 

 tion ill length and stoutness within the limits of the same species. 

 The two forms of greatest importance are those I have called symmetric 

 and asymmetric. The Germans speak of the former as " spindel- 

 formig." In the asymmetric forms the outline of the segment is much 

 less convex on its inner than on its outer aspect and the actual tip 

 looks more or less blunt. The symmetric, or spindle shape, would 

 offer a nearly circular outline of a transverse section, and the tip in 

 most cases appears' more pointed. The spindle in Empleurus rvgosus 

 is very slender and pointed, while in Atracthelophorus arvernicus it is 

 short and thick. The genus Meghelophorus has a peculiar maxillary 

 palp, in some respects intermediate in sha^^e, but with the penultimate 

 joint longer and thicker than in the other forms. Although it is very 

 difficult to give an exact description of these three kinds of maxillary 

 palpi, yet the difference to an educated eye is sufficient to enable one 

 to give a good opinion as to the relations of the species or genus. 



The prothorax is very important in Helophorini. The pleuron is 

 joined to the notum by a distinct suture, as in the Caraboidea. This 

 suture is very distinct in Empleurus, and is placed at a considerable 

 distance from the raised margin that limits the upper surface of the 

 notum. In Helo-phorus the suture is less distinct and is placed nearer 

 to the notal margin. The pleuron is dull, being covered by a minute 

 pubescence, but the area between it and the notal margin is generally 

 highly polished. This space may be called the supra-pleural area. 



The anterior coxal cavities are usually described as open in the 

 Helophorini, but this arises from tlie examination of undissected 

 specimens. If the front legs are extracted it is seen that the foramen 

 is closed behind by the junction of a process of the prosternum with 

 the pleuron, but not with the tip of the pleuron, which in fact projects 

 as a large free process. 



The shape of the pronotum exhibits characters that divide the 

 Helophoririi into two groups. In Empleurus the front margin is very 

 irregular in outline, being convex in the middle, then concave on each 

 side, then again sloped forward to the front angles. This peculiarity 

 is accentuated by tire surface being more or less arched perpendicularly 

 over the head, so that the middle of the pronotum forms a sort of hood 

 over the head. In other forms, such as Meghelophorus, this hooding 

 of the thorax is only faintly indicated. The transitions between these 

 two forms of pronotum are to be found in the genus Eutrichelophorus, 

 a genus which till now has not been distinguished from Trichelo'phorus. 



