574 Mr. D. Sharp and Mr. F. Muir on the Comparative 
small median foramen at base. Lateral lobes as long as median 
lobe, the basal half of each embracing the side of the basal half of 
the median lobe, the distal half narrow and curved. Basal-piece 
very small. Internal sac small with a large patch of long brown 
hair but no armature. 
Mitophyllus parryanus. 
Closely allied to Ceratognathus. Median lobe well developed, 
cylindrical, slightly constricted near the tip and rounded at the base ; 
median orifice at the distal end, membranous round the orifice and 
from there graduating off to strong chitin on the rest of the lobe ; 
small median foramen at base; point of articulation on dorsal side. 
Lateral lobes twice as long as the basal-piece, reaching to the end, 
and embracing the sides, of the median lobe. Basal-piece about 
one-third the length of the tegmen, with small basal opening. 
Internal sac small, covered with fine brown hairs, but no armature. 
Mitophyllus vrroratus. 
The basal-piece has quite disappeared, the lateral and median 
lobes as in Ceratognathus, but the basal parts of the lateral lobes 
entirely envelop the basal part of the median lobe. Internal sac 
small with very dense covering of chitinous, elongate, pointed 
scales; the ejaculatory duct long and coiled up in the median 
lobe so as to allow enough slack when the sac is evaginated, 
An important difference exists between this species and M. par- 
ryanus. 
In these forms the muscles for working the median lobe are 
attached to its base, there being no median struts. 
Syndesus cornutus (Pl. XLIII figs. 6, 6a, and 60). 
The median lobe is well developed, bottle-shaped, with the median 
orifice at the distal end and the small median foramen at the base (mf), 
around which the chitin is much thicker and stronger and supports 
the point of articulation and the attachment of two median struts. 
Lateral lobes broad at the base and bluntly rounded at the tips 
which reach slightly beyond the tip of the median lobe ; the bases 
of the lateral lobes embrace the sides of the base of the median lobe. 
Basal-piece large and shield-shape, membranous on the dorsal side. 
The internal sac without armature but very long (21 mm.) and 
doubled up in the median lobe. The median foramen is very small 
and it is not likely that the ejaculatory duct passes through when 
the sac is evaginated, consequently only half the sac can be 
evaginated. 
