546 Mr. D. Sharp and Mr. F. Muir on the Comparative 
Chalcolepidius albertisi (Pl. LX VII fig. 156). 
Median lobe slender, chitinous above and on sides, membranous on 
ventral face ; median orifice near tip on ventral face, base produced 
into two long median struts. Lateral lobes a little shorter than the 
median lobe, flattened horizontally and deeply cleft on outer edge 
about half way down (a) nearly dividing them into two pieces; their 
bases meeting on the dorsal aspect. Basal-piece very long and divided 
into two sclerites, one long V-shape (b), a more basally placed piece 
running round the basal edge (c); dorsalaspect membranous. 
Internal sac undifferentiated. 
The aedeagus in Elateridae is as a rule a generalised 
trilobe type, becoming compressed and asymmetrical in 
Anisomerus. The division of the lateral lobes and basal- 
piece into two in Chaleolepidius is interesting. It is a 
more differentiated form of the family, which seems to be 
on the whole rather monotonous and uninteresting, 
Family THROSCIDAE. 
Forms examined: Zhroscus dermestoides L., England. 
LInssomus bicolor Chevr., Mexico. 
Figs. 157 and 158 Pl. LX VII. 
The aedeagus of this family is a tri-lobed form near to Elateridae. 
In 7. dermestoides, fig. 157, the median orifice is on the ventral 
aspect near tothe base and the basal-piece is large and well de- 
veloped. In Lissomus bicolor (Pl. LXVIT figs. 158, 158) the basal 
piece is membranous (m) in the centre on the ventral aspect, and 
the chitin forms a ring; the median orifice is on a membrane on 
the ventral aspect of the broad, flattened median lobe. The internal 
sac is undifferentiated. 
Family EUCNEMIDAE. 
Form examined: Henviopsida mastersi Macl., Australia. 
Wig, 159. Pl LXV Le 
Median lobe short, forming a pointed, chitinous plate on the dorsal 
aspect, prolonged into two long median struts. Lateral lobes large, 
consolidated together at the base to form a tube, the distal ends 
spatulate and twisted. Basal-piece very small, forming a round 
sclerite on the ventral aspect. Fig. 159 shows the internal sac (7s) 
partly protruding. 
Near to the Elaterid type, but the detached, small 
basal-piece may prove to be distinctive. 
