2 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



This genus is erected to receive the remarkable species Corym- 

 bites trapezium of Leconte 1 (Plate I, fig. h), from Texas, of which 

 Corymbites trapezicollis Schw. 2 is a synonym. Schwarz refers 

 this species to the genus Ludius, 9 so the synonymy will stand as 

 follows : 



Perissarthron trapezium (Lee.) Hyslop 



Corymbites trapezium Lee. 

 Corymbites trapezicollis Schw. 

 Ludius trapezium (Lee.) Schw. 

 Ludius trapezicollis (Schw.) Schw. 



This species has generally been described as having eleven 

 joints with the llth strongly constricted or appendiculate. This 

 is an error, the so-called constriction really being a distinct seg- 

 mentation (fig. f), as can easily be demonstrated with a relaxed 

 specimen as the 12th moves freely on the true llth segment and 

 cannot be compared with the condition of constriction found in 

 certain Melanactes and several species of true Ludius (Corymbites}. 



Through the ki'ndness of Dr. Skinner of the Philadelphia Acad- 

 emy of Natural Sciences, I have had the opportunity of examin- 

 ing the female of this species in the Horn collection. It differs 

 from the male in the pronotum being as wide at the middle as at 

 the posterior angles, with the sides strongly arcuate^ The anten- 

 nae when directed backward do not attain the posterior angles, 

 consequently joints 4 to 11 are materially shorter in comparison 

 to their diameter than in the male. 



The genus will probably fall into the tribe Ludiini but its posi- 

 tion cannot be definitely ascertained until the larva has been 

 described. 



Pyrophorus Illiger. 



This genus was established by Illiger in 1809< to include those 

 species of the Elateridae having luminous vesicles on the pro- 

 notum. This character serves to identify the genus, which is 

 confined to tropical America, both North and South, and the 

 West Indies, with the exception of a few forms which agree with 

 this genus in all characters, save the luminous spots. But one 

 species has been recognized from North America north of Mex- 



1 Proc. Acad. Nat. Sc. Philad., Vol. 18, p. 392, Dec., 1866. 



2 Deut. Ent. Zeit., 1903. 



3 Gen. Ins. 



4 Mag d. Gesellsch. Nat Freund. Berl I. D. 141 1809 



