Anatomy of the Male Genital Tube in Coleoptcra. 588 



Heliocopris mmihotiis. 



Median lobe small, entirely liidden and embraced by the lateral 

 lobes. Lateral lobes ratlier large, with a membranous connection 

 to near their tips, which membrane folds together when the lateral 

 lobes approximate. Basal-piece large, forming an irregular chitinous 

 tube, curved and enlarged at the base, with a large basal opening. 

 Internal sac large, with two blunt, flattened, chitinous spines near 

 apex. 



Onthophagics fracticornis. 



Median lobe small, with small chitinous support at base projecting 

 into basal-piece as two short, broad, rounded, median processes (cf . 

 Oniticellus). Lateral lobes small, connected by membranes to near 

 their tips. Basal-piece large, forming chitinous tube with large basal 

 opening at base. Internal sac large, bearing complex, curved 

 chitinous plates on the apical half. 



Oniticellus marsyas. 



Tambour cylindrical, basal portion short. Lateral lobes short 

 and powerful, abruptly flexed, of irregular, complicated form ; their 

 median aspects contiguous throughout. Median lobe entirely 

 concealed, forming at the base a chitinised tray, basally split for 

 two-lifths of its length and forming a secondary tambour within 

 the normal one. Sac largely developed. This is a very remarkable 

 and high form of Coprinae, though the affinity with Onthophayns is 

 a close one. 



Obs. — The Coprinae have the basal-piece rather com- 

 pletely tubular in form, owing to the shortening of the 

 basal part of the " tambour," The basal part of the 

 tambour (or great basal sclerite of the Scarabaeidae) is 

 chitinous on one aspect, membranous on the other, and 

 this basal portion being in Coprinae of small elongation in 

 comparison with the distal portion, the tubular form of 

 the distal portion is unusually conspicuous. The aedeagus 

 of Coprinae is easy of recognition. 



Aphodius imnctato-sukattts (PI. XLV figs. 18 and 18a). 



Median lobe small and membranous, supported on the dorsal edges 

 by two chitin strips (a) which project into the basal-piece as two struts 

 (ms) for the support of muscles ; median orifice occupying all the 

 dorsal face. Lateral lobes large, a semi-chitinous extension along 

 the dorsal edges {b) form two flanges which overlap and hide the 

 median lobe. Basal-piece large, the distal half forming a tube, the 



