1927] The Male Genital Tube of the Genus Scymnus 169 
less chitinized and is looped around the median strut. The 
lateral lobes are large as compared with the basal lobe. 
In the second group which consists of americanus Mills., 
punctatus Mels., cervicalis Muls., and terminatus Say, the proxi- 
mal end of the median lobe shows specific variations. In fact 
the proximal end of the median lobe, and the basal lobe, are the 
structures which are most variable in all the groups. 
The cedagus of nanus Lee., semiruber Lee., cinctus Lee., and 
hcemorrhous Lee., ate larger than the oedagi of the second group. 
All of the drawings were made at a magnification of about 115 
diameters, except in the case of americanus and puncticollis , 
which were magnified about 85 diameters. The proximal end of 
the median lobe in nanus and semiruber are somewhat alike, and 
resemble that of terminatus to a certain extent. The same area 
in cinctus and hcemorrhous has in addition a small area, in the 
upper portion of which are found alternate bands of thick and 
thin chitin. The basal lobe is also much modified in cinctus and 
hcemorrhous. It extends through the basal piece, and beyond it 
anteriorily, for a short distance. Possibly if more material were 
available, there would be two groups instead of one, nanus and 
semiruber belonging to one, and cinctus and hcemorrhous to the 
other. 
The basal lobe of puncticollis Lee., consobrinus Lee., and 
tenebrosus Muls., is much expanded, and very much larger thap 
the lateral lobes. The shape of the basal lobe is also rather com- 
plicated in structure and projects beyond the basal piece an- 
teriorily. At the distal end of the median lobe there are several 
stiff, bristle-like projections which point forward. There are also 
specific differences in the proximal end of the median lobe. 
If we consider the genitalia of consobrinus and tenebrosus it 
would appear that these species are closely related, while in the 
key they fall into separate groups, and their relation would never 
be suspected. The genitalia of the Coccinellidse are rarely ex- 
truded and are rather difficult to dissect out, for this reason they 
will never be of any value as key characters, as in the case of 
other groups. However, further study of the genitalia of the 
genus Scymnus will undoubtedly show the relationship between 
the various species. 
