Ill OBSERVATIONS ON THE AMERICAN POGONIN^, 



INCLUDING TRECHUS. 



The Pogoninee, as organized by LeConte and Horn, comprise 

 but few genera, but these differ from each other very much in gen- 

 eral habitus, as well as special structural characters, and the usual 

 custom now is to restrict the Pogoninae to Pogonus and a few related 

 genera and subgenera, such as Cardioderus , Syrdenus and Pogonistes 

 and to make of Trechns, Anophthalrmis, Patrobus and some others 

 a separate subfamily the Trechinae; but, as my material will not 

 permit me to go deeply into the subject, I desire at the present time 

 to give synopses of merely the four genera Patrobus, Platidius, 

 Trechns and Anatrechus, as now represented in my collection. 



Patrobus Steph. 



The body in this genus is of moderate to rather small size, some- 

 what ventricose, with moderate head, prominent eyes and very 

 slender palpi, the last joint of the maxillary always distinctly longer 

 than the third. The prothorax is more or less cordiform, with very 

 deep basal foveae, which are irregularly rounded and always coarsely 

 punctate and with a short fine carina near the lateral edge basally, 

 the median stria deep, subentire and becoming coarser and deeper 

 at base; the anterior transverse impression is punctate and usually 

 deep, but in some species, such as Iceviceps and insularis, it becomes 

 obsolete medially, leaving only a somewhat evident broad apical 

 beading. The elytra have punctured striae, the scutellar always 

 long and parallel to the suture, the first stria gradually outwardly 

 oblique at base, ending near the point of origin of the second stria. 

 The subapical sinus is subobsolete, the base not margined, except 

 by a slight incurvature of the lateral margin, and the submarginal 

 line of ocellate punctures is feebly developed. The discal punc- 

 tures are three in number, but in rnfipes, LeConte mentions four 

 possibly however an abnormal condition. The legs and tarsi are 

 slender, the male having the first two joints of the anterior tarsi 

 very moderately dilated. The sterna are all coarsely punctured as 



394 



