256 [December 



of the base, is a large round groove with a smooth bottom and a. distinct 

 puncture in the centre; before the groove, the thorax is suddenly ele- 

 vated, forming the acute end of the median ridge of the thorax ; on each 

 !«ide of the groove at the base is a small tubercle. The elytra are trun- 

 cate at the sutural posterior angles, with tufts of yellow hair at the 

 middle and outer angle. The abdomen is widest at the base, wider 

 than the elytra at the tip, excavated from one side to the other, with 

 a large smooth tubercle each side at the base on the margin. The lesrs 

 are in proportion longer than in roerua, the anterior coxse are cylindri- 

 cal, prominent, the intermediate globose, the posterior transverse. 



The male diifers in the above mentioned striae on the vertex, the 

 i)itermediate tibiae being sinuous inside and armed with a very small 

 spur at the end, the intermediate trochanters being armed with a strong 

 cylindrical spine, and the metastcrnum, which is in the female lancet- 

 .vhaped reaching between the hind coxae, is in the male much elevated, 

 truncate and bifurcate before the posterior coxje; between the latter are 

 two punctures and a tuft of hair. 



One 9 W3S found by me some six years ago in Illinois, and speci- 

 mens of both sexes were lately collected in large numbers by Mr. Chas. 

 Sonne, in Chicago. 



The honor of havir;g discovered it to be a new species is due to Dr. 

 John L. LeConte. The discovery of the male belongs to Mr. Sonne. 



2. Bryaxis velutina is identical with Decarfhron formicefi. 



.3. Bryaxis clavata (Var. conjuncta). — Nigra, nitida, elytris piceis, capite tri- 

 foveata, thorace globoso, foveis tribus siilco arenato connexis, antennis raarit; 

 articulis tribus ultimis valde elevatis. Long 2.0 ni. m. 



Separated from B. conjuncta, of which it differs by the antennas of 

 the male having the 1 — 2 joint subequal cylindrical, the 3 — 4 small 

 globose, the 5 — 6 equal, larger, globose, the 9 — 10 much enlarged, 

 transverse, very hairy, forming with the last, ovate, acute joint one 

 thick club. 



I consider it to be the northern climatical form of B. conjuncta. 



This species with B. conjuncta , dcntata, alxlominaUs, and the two 



following form one conclave, having the base at the thorax transversely 



sulcate and distinguish themselves as follows: 



First abdominal segment of the male entire B. conjuncta and clavata. 



First abdominal segment behind produced in a lobe...B. dentata. 

 First abdominal segment behind produced in two acu- 

 minate lobes B. Illinoiensis. 



First and second segment with two lobes B. Floridana. 



The three first segmentB with two lobes each B. abdominalis. 



