96 [May, 



b. Capite rotundato, occipite breviter impresso, thorace postice constricto, 

 elytris basi impressis. Sp. 4 6. 



c. Capite rotundato, occipite non impresso, thorace postice rrodice constricto, 

 elytris non impressis : corpus minus pubescens. Sp. 7 9. 



d. Capite subquadrato, thorace elongate, trapezoideo ; corpus vix pubescens. 



Sp. 1013. 



e. Capite subquadrato, thorace plus minusve trapezoideo, elytris non impres- 

 sis ; corpus longius pubescens. 



1. Capite postice rotundato, thorace subcampanulato ; antennis tenuibus. 



Sp. 1418. 



2. Capite postice truncate, pone oculos non angustato, oculis prominulis. 



Sp. 1936. 



3. Capite postice truncate, pone oculos non angustato, oculis parvis ; 

 elytris lateribus retundatis, humeris fere nullis. Sp. 37. 



B. Caput non granulatum ; tibiae calcaribus obsoletis ; thorax basi non 

 marginatus. Sp. 38. 



C. Caput triangulare, granulatum; tibiae calcaribus valde distinctis : 

 thorax ovatus basi marginatus. Sp. 39 40. 



1. A. obscurus, niger nitidus subtiliter pubescens, capite impunctato, 

 thorace postice constricto, basi cylindrico, elytris parcius punctulatis, versus 

 basin vix cinerascentibus, antennarum basipicea. Long. '12. 



Ferte, Anthic. 116. 



Coney Island, near New York. July, in salt marsh. The elytra are less 

 impressed behind the base than in the following. The posterior tibiae of the 

 male are not dilated, or bent. 



2. A. nitidulus, niger nitidus, subtiliter pubescens, capite parce punc- 

 tate, thorace postice constricto, basi cylindrico, elytris parce punctulatis, basi 

 vix cinerascentibus, antennarum basi picea. Long. '12. 



Lee. An. Lye. 5, 153. 



Two specimens, San Jose, California. Exactly similar in size and form to 

 the preceding, but differs by the head being punctured, and the elytra more 

 deeply impressed towards the base. 



3. A. elegans, rufo-piceus, subtiliter pubescens, capite vix punctato, thorace 

 postice constricto, basi cylindrico, elytris punctulatis, nigris, basi indeterminate 

 rufis, et cinerascentibus. Long. "12. 



Ferte, Anthic. 117. 



Georgia and Missouri Territory. I have always considered this species 

 as A. cinctus Say, but, after renewed investigation, feel inclined to 

 adopt Ferte's conclusion, that Say's species is more allied to A. formicarius. 

 The expression " elytra hirsute " will by no means apply to the present species, 

 nor is there ever a cinereous spot at the tip of the elytra. The male has the 

 posterior tibiae dilated and sinuated internally. 



4. A. tenuis, niger opacus, tenuiter pubescens, capite dense punctulato, 

 occipite breviter canaliculate, thorace postice constricto, basi cylindrico, elytris 

 vix impressis subtilissime punctulatis, fascia ante medium angusta albida, 

 antennis palpis pedibusque testacis. Long. -12. 



Lee. An. Lye. 5, 153. 



Colorado River, California. Approaches very close to the preceding species 

 in form, but the last joint of the palpi is longer than wide. The anterior part of 

 the thorax is less globose than in A. formicarius, with which, however, it agrees 

 so closely in the form of the body and structure of the palpi, that it would be 



