OARABIDAE. 31 



except in Amara, and with two supra-orbital setigerous punctures, 

 clypeus prolonged beyond the base of the mandibles, the latter 

 witiiout setigerous puncture externally. Maxillae ciliate or spinu- 

 lose within, hooked at tip (except Stomis and Agelsea), the palpi 

 of moderate length and of variable structure. Mentum broad, of 

 variable length, usually deeply emarginate and toothed, varying 

 to a simple bisinuation; ligula at least moderate in size, often 

 large, more or less free at tip and bisetose (quadrisetose in Myas), 

 the paraglossse slender and usually longer than it, sometimes 

 much longer (Stomis, Loxandruf^), the palpi variable in form, 

 the second joint sometimes longer than the terminal. Thorax 

 with at least one setigerous puncture at the side, and one at the 

 hind angle. Body not pedunculate (subpedunculate in some 

 Evartlwus), scutellum distinct. Elytra narrowly inflexed, mar- 

 gin strongly interrupted posteriorly and with a well-marked 

 internal plica, disk usually with dorsal punctures. Prosternum 

 not prolonged at tip, margined or not. Mesosternum oblique or 

 vertical in front, rather widely separating the coxae, the epimera 

 narrow and often wider internally than externally. Metasternum 

 and side pieces variable in length, the epimera always distinct, 

 posterior coxjb contiguous. Middle and posterior tibiae variably 

 spinulose externally, the anterior slightly so near the tip, the 

 latter broader at tip, deeply emarginate within, the inner spur 

 situated at the summit of the emargination. 



The anterior tarsi of the male have three joints rather broadly 

 dilated and squamulose beneath. 



This tribe is represented in our fauna by but one group, Ptero- 

 stichi. Plcrodichus and Amara occur on both sides of the 

 continent; the others in the Atlantic r»gion only. The genera 

 are not clearly limited, and as reduced by recent studies may be 

 separated by the following table : — 



Terminal joint of palpi dilated. Elytra without dorsal puncture. Myas. 

 Terminal joint of palpi cylindrical or slightly oval. 

 Anterior tarsi of male normally dilated. 



Terminal joint of palpi as long as or longer than the penultimate, t1»e 



latter bisetose in front. Pterostichus. 



Terminal joint of palpi shorter than the penultimate, th(! latter plii- 



risetose in front. 



Elytra with one dorsal puncture. Evarthrus. 



Elytra without dorsal puncture. Amara. 



Anterior tarsi of male obliquely dilated. Lozandrus. 



