BY EUSTACE W. FERGUSON. 537 



The three foregoing species, P. mirahilis, ^. rufolineata, and 

 P. Cocci, form a triad of species so closely allied that, while it is 

 possible to point to outstanding types of each, yet intermediate 

 specimens run each other so close that it is well nigh impossible 

 to clearly define the limits of each. 



P. mirahilis Kirby, has the elytral sculpture more irregular 

 and confused, the granules on the intermediate interstices 

 detached from one another, and, as a rule, not continued to the 

 base or apex. 



P. rufolineata Macleay, has the elytral sculpture finer than in 

 P. Coxi, and more regular than in P. mirahilis. The protho- 

 racic granulation also affords a point of distinction; in P. rufo- 

 lineata it is rather finer and closer than in P. mirahilis. The 

 forceps are slightly stronger than in P. mirahilis. 



P. Coxi Macleay. — Typical examples of this species are much 

 larger than those of the other two species, and have the elytral 

 sculpture more regular, the transverse rugae being much larger, 

 and more prominent; the prothoracic granules are, as a rule, 

 larger than in the other species, but the last feature varies in 

 different specimens, especially in the female. The forceps are 

 larger and stronger than in P. mirahilis. 



P. reticulata Boisd, — The type is a female, but undoubtedly 

 belongs to this group; unfortunately it is not absolutely possible 

 to refer it either to P. mirahilis or to P. rufolineata; it has the 

 prothoracic granulation fine, as in P. rufolineata, but the elytral 

 sculpture is exactly as in female specimens of P. mirahilis, the 

 granules being separate and nowhere duplicated. 



While I think it well, for convenience, to retain both P. rufo- 

 lineata and P. Coxi as species distinct from P. mirahilis; it is 

 highly possible that they should be considered as varieties only. 



P. reticulata Boisd., I place as a synonym of P. mirahilis, 

 with only a slight degree of hesitation. 



The other members of the " gular-horn-group " can be dis- 

 tinguished without trouble, P. verrucosa by its extremely coarse 

 prothoracic and elytral granulation, and P. cancellata by its 

 peculiar costate elytra. There are, however, several other species 



