122 GEO. H. HORN, M. D. 



a tooth as long as the upper, inner claw simple; posterior leg— claws as in the 

 middle leg. Fourth joint of middle and posterior tarsi with a spiniforrn pro- 

 longation at apex heneath. 



P. brevipes Lee, the only species known, is at all times a rare 

 insect and until now the material at hand did not admit of the 

 sacrifice of a specimen for dissection. The figures on the accom- 

 panying plate give an idea of the general form of the species as 

 well as of its details. 



Since the first description of the species (Proc. Acad. 185G, p. 23), 

 the position of the genus has remained in doubt. In the Classification 

 of the Coleoptera of North America it is placed in the tribe Orycto- 

 morphi, a division of the Dynastide series. Our later studies show 

 that Polymoechus is allied rather to Parastasia an East Indian genus 

 associated with Rutela by Lacordaire. 



The genera of Scarabaeidae seem to need revision, especially in 

 the entire Pleurostict series. The Melolonthidaa are not satisfactorily 

 grouped, the Cetonide genera not at all defined, while much remains 

 to be cleared up in the doubtful ground between the Rutelides and 

 Dynastides. 



Details of structure will be found on PI. VI, figs. 5 — 12. 



APHONUS Lee. 



Details of the structure of the oral organs are given on PI. IV, 

 fig. 13, in order that comparisons may be made between Polymoechus 

 and Aphonics, the former being now referred to the Rutelini, the latter 

 a true. Dynastide superficially resembling Polymoechus. 



ELATERIDiE. 



Since the days of Latreille many attempts have been made to define 

 the families of that division of the serricorn series named by that 

 author the Sternoxes, containing the Buprestidae, Throscidaa, Eucnemidaa, 

 Elateridae, Cerophytidae and Cebrionidse, as they are accepted by one 

 or other author. 



The first two families are not only abundantly distinct from each other 

 but possess characters which sharply separate them from those which 

 follow. The last four families do not present any characters which are 

 defined with sufficient sharpness to warrant their separation. 



In the preceding volume of these Transactions I have attempted to 

 demonstrate that the Cebrionidaa are not separable from the Elateridae, 

 the tribe Plastocerini filling the space which formerly existed between 

 the two families. 



The Eucnemidas on the other hand seem more sharply defined. 



