NO. II LARVAE OF THE ELATERID BEETLES GLEN 21 



within cuticular depressions; minute, dark "sensory" structure just 

 ventrad to each pair ; sometimes with one or more minute setae caudad 

 to ventral pair. Eye spot {e) black, well defined, ovate or circular, 

 just caudad to ventral margin of base of antenna ; surrounded by 4 or 

 5 setae, including the anteroepicranial setae {aed, aev) so designated 

 by Hyslop and Boving (1935, p. 50). Hypostoma {hs, fig. 4, a) with 

 strongly sclerotized mesal margins to which ventral mouthparts and 

 hypopharynx attach. Postgenal areas {pge, fig. i, &) expanded mesad, 

 but always rather widely separated; glabrous. 



Gula {gu, fig. i, h) short, wide, glabrous; defined laterally by 

 anterior extensions of postoccipital sutures {pos) which terminate 

 in indistinct posterior tentorial pits {ptp) at bases of cardines. 



Antennae {ant, figs. i,a,h; 2, g; fig. 2, a, d) three-segmented. First 

 joint (/) clavate, one-half to two-thirds as wide as long; without 

 setae; 3 or 4 small pores. Second joint {2) subcylindrical, almost 

 as wide as long; about one-half length of basal joint; without setae; 

 I or 2 pores ; a few small "sensory" pegs borne distally ; i medium- 

 size4 conical "sensory" appendix (sap) just ventrad to base of third 

 joint. Terminal segment (j) small, about half as long as second 

 joint and one-third as wide; 4 setae on apex. 



Mandibles {md, figs, i, a, h; 2, g; fig. 2, e, f, h) alike, of moderate 

 length, robust; two-thirds as wide at base as long; anterior half 

 inward bending at an angle of approximately 45° ; retinaculum {ret) 

 well developed. Base triangular, mesally acute ; well-developed con- 

 dyle {co) and socket {soc) for articulation with epicranial plate 

 and talus, respectively. Proximal half tapering distally; ventral sur- 

 face slightly granular just laterad to penicillus; smaller granular area 

 on dorsal surface; outer aspect with profound antennal fossa and 

 two setae; penicillus {pen) present, sometimes reaching base of 

 retinaculum. Distal half pointed; outer surface convex with deep 

 dorsal groove {dg) ', inner face slightly excavate with small median 

 carina {mc), sometimes worn away, ventral margin {vm) of inner 

 face sharp and slightly convex ventrally, dorsal margin {dm) sharp 

 and strongly convex dorsally. 



Ventral mouthparts {vmth, fig. 2, g; fig. 9, h), excluding ap- 

 pendages, almost as long as sides of head ; moving as a unit forward 

 and backward, usually in a horizontal plane, with cardines acting 

 as hinges ; whole unit from two-thirds to three-fourths as wide at 

 bases of stipites as at anterior ends of stipites. 



Maxillae (fig. 3, c) well developed. Cardines {cd) moderately 

 large, subtriangular, well separated; posteriorly attenuate, ending 



