90 GEO. H. HORN, M. D. 



is present it may be close to the eye, usually it is a little removed, it is 

 never in front of the middle. 



The clypeus also bears setae, usually one on each side and as a general 

 rule those genera with two supra-orbital setae have the clypeal seta situ- 

 ated at the middle of the side of the clypeus at a slight distance from the 

 margin, while those with one supra-orbital have the clypeal near the an- 

 terior angle. Rarely there are more than one clypeal setae at the side, as 

 in certain Anisodactylus while in Pelecium {ci/anipes) there is no seta 

 whatever it being apparently replaced by a considerable development of 

 the outer seta of the labrum. 



Eyes. — These organs are sometimes entirely absent, the instances are 

 now rather numerous and well known. When present the form shows 

 but little variation from the round or oval form (see Ozsenini). Their 

 size however varies greatly and with it the prominence, Siagona having 

 very small eyes and in Elaphrm they are large and prominent. When 

 the eyes are large relatively to the size of the head, whether unduly 

 prominent or i^t, they approach very closely beneath the head to the 

 edge of the buccal fissure, when small they are distant from the mouth. 

 This seems to be very useful systematically but has not been made use 

 of before the present paper. The granulation also varies but I have not 

 been able to make use of this. 



Antenna. — These are always eleven-jointed, usually filiform or seta- 

 ceous, sometimes moniliform or compressed. The form seems to have less 

 value from a systematic point of view than the extent of fine pubescence 

 covering the surface of the joints. The antennae have three kinds of 

 pilosity, sometimes all present at the same time. First, a dense, fine, 

 short, recumbent pubescence which is present on those joints with a fine, 

 dense punctuation indicating probably the presence of a special sense 

 identical with or resembling the sense of smell in animals of a higher 

 organization. Second, a longer hairyness diiFusely scattered over the joints, 

 and finally stifFer hairs around the distal ends of the joints, these are 

 especially well marked in Loricera and allied genera. The basal joint is 

 not at any time very long but in the Scarites and Dryptini sufiiciently 

 elongate to attract notice, on the anterior face of this joint near the tip is 

 a long seta. The extent to which the pubescence covers the antennae 

 has been used by many systematists since Lacordaire but there are so 

 many striking exceptions within tribal limits that it can only be used for 

 separating tribes and never for defining any higher groups. The surface 

 of the antennae is not always uniformly punctured. In those genera with 

 the ant(!nnae at all flattened, one or both sides have a median smooth 



