500 SEEEICOENIA. 



of the prosternal process, a character overlooked by Candeze and others, and one which 

 may eventually be considered to be of generic value *. Good differential characters 

 are also to be found in the form of the prosternal sutures, the exterior of the two being 

 in some species almost completely obliterated, and in others sharply defined, with the 

 enclosed space impunctate. Our species all belong to Section III. of Dr. Candeze's 

 Monograph. 



a. Prosternal process extended in the plane of the prosternum to the ante-apical 



tooth; intercoxal portion of the mesosternum declivous. 

 a'. Outer prosternal suture almost obliterated, the propleural punctuation 

 extending inwards; third joint of the antennae much longer than the 



second ; elytra ohsoletely striate. Species large and robust cylindricollis. 



V. Outer prosternal suture usually well-defined (except in L. tropicalis), the 

 space enclosed impunctate or nearly so. Species smaller and narrower. 

 a". Third joint of the antennas not, or not very much, longer than the second. 

 a"'. Elytra moderately elongate, at most obsoletely striate. 



a*. Punctuation of the prothorax sparse and coarse, that of the elytra also 



sparse and rather rugose ; antennae very elongate in the male . . . nigricollis. 

 £ 4 . Punctuation of the prothorax rather close and coarse, that of the 



elytra fine and close ; antennas short in the male isthmicus. 



c\ Punctuation dense and moderately coarse, that of the elytra fine and 

 close ; antennse moderately elongate in the male. 

 a 9 . Prothorax opaque, very densely punctured; pubescence dense; 



antennae with joints 2 and 3 subequal subsericeus. 



b s . Prothorax subopaque, densely punctured ; pubescence sparser ; 



antennas with joint 3 distinctly longer than 4 mbopacus. 



V". Elytra comparatively short, deeply punctate-striate breviusculus. 



b". Third joint of the antennas nearly equal to the fourth; punctuation of the 



prothorax and elytra close ; elytra obsoletely striate tropicalis. 



b. Prosternal process gradually declivous behind the coxse; intercoxal portion 



of the mesosternum declivous, not or feebly raised anteriorly; third joint 

 of the antennas slightly longer than the second, 

 c'. Outer prosternal suture almost obliterated, the propleural punctuation 

 extending inwards. 

 c". Elytra rather coarsely punctate-striate ; body moderately convex . . . rubicundus. 

 d". Elytra very finely striate ; body very elongate, depressed, subparallel . . depressus. 

 d'. Outer prosternal suture well-defined, the space enclosed impunctate ; body 

 rather elongate, moderately convex; elytra narrowing from the base, 

 punctate-striate physorhinus. 



c. Prosternal process abruptly and perpendicularly declivous a little behind the 



coxas, and subhorizontally extended thence to the ante-apical tooth; the 



* Lewis, in his paper on the Elateridas of Japan [Ann. & Mag. Nat. Hist. (6) xiii. p. 266], applies the name 

 Ludius to the first group, and Crigmus, Lee., to the third group ; he takes L. hepaticus, Germ, (nee Lee.), as 

 the type of Crigmus, but, unfortunately, neither of the two species originally included in Crigmus possesses 

 the characters he assigns to it. 



