LUCANIDiE. 141 



ii. RECTOCERA. 



Having finished the petalocerous or rather orthocerous Lamellicorn beetles, we 

 must next proceed to those the stalk of whose antennae mostly forms an angle with 

 the scape, so that these organs appear as if they were broken, which, as was before 

 observed, 2 form one branch of Mr. Mac Leay's Rectocerous beetles. These are 

 not to be regarded, though they exhibit an analogical relation, respect being had 

 to their food, 3 as following the Trichiadce in the line of affinity, but in order to 

 link them to their apparently nearest relatives, we must retrace our steps to the 

 Histeridce, where we shall find a tribe that are lignivorous, of a depressed form, 

 and with more than usually protended mandibles, of which Hololepta maxillosa 

 may be regarded as the type : 4 it is towards these that the Lucanidce appear to 

 tend, at one extremity, though still many forms are wanted to fill the interval. 



Although I have not altered Mr. W. S. Mac Leay's denomination of the tribe 

 before us, it must be observed that, in some families belonging to it, as the Lam- 

 primidce, Passalidcs, &c. the antennae are not broken. The family last mentioned, 

 the Passalidcs, is not only distinguished by the stalk of the antennae not forming 

 an angle with the scape, as in the Lucanidas ; but the form of the insects that com- 

 pose it, is narrower, more cylindrical, and less depressed. From this family, as 

 we shall see hereafter, a branch appears to diverge, by the Bostrichidans to the 

 great Rhynchophorous tribe. 



Family LUCANIDiE. Lucanidans. 



LXXV. Genus PLATYCERUS. Lat. 



(192) 1. Platycerus piceus. Plceous Platycerus. 



Lucanus piceus. Web. Obs. Ent i, 84, 2. Fab. Syst. Eleulh. ii, 252, 20. Illig. Mag. i, 249. Tbunb. Mem. Nat. de 

 Mosc. i, 202, 30. Schon. Si/n. iii, 327, 31. 



frontosus. Knocb. 



Length of the body 6 lines. 



A single specimen taken in the Journey from New York to Cumberland-house. 



See above, p. 122. 3 The Trichiadce as well as the Bectocera feed on putrescent timber. 



4 Oliv. Ent. i, 8, 1, 1, t. ii, iii,/. 8. 



