574 Mr. D. Sharp and Mr. F. Muir on the Gomparcdive 



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 parryan us . 



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 irroratus. 



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- 

 ryantis. 



In these forms the muscles for working the median lobe are 

 attached to its base, there being no median struts. 



Syndesus cornuius (PL XLIII figs. 6, Go, and &)). 



The median lobe is well developed, bottle-shaped, with the median 

 orifice at the distal end and the small median foramen at the base ()«/), 

 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. 



