the stem or Curricle. Even those undeniable habitual analogies which the 

 genus lias with the Dynastini in color, sculpture of elytra, prolongation 

 of front, homed head, indented thorax, &c, cannot obtain against this 

 decisive character; though it was these very points, which are not usual 

 in the Melolonlhidce, which prevented the recognition of the genus as a 

 member ol that group and led to its association with entirely heterogenous 

 forms. 



In fact Pleocoma does not onlv not lack any of the characteristics ol 

 a Melolonthid antenna;, but even possesses all the peculiarities in the most 

 prominent form. To be sure, against this, the number of joints, eleven, 

 might be urged, as all hitherto known genera possess only 8-, 9-, or 10- 

 jointed antennae. But in view of the ahead) known variability in number 

 of antenhal joints the further increase by one could be the less surprising, 

 as eleven is evidently the original and normal number, and the decrease' 

 to 10, 9 and 8 can be considered only an departure from the normal 

 structure, although it is one which among the Lamellicorns is wide- 

 spread. At all events the Pleocoma antennas show — if we ignore one of 

 the short joints of the funicle winch at any rate vary in number — entirely 

 the structure of a Mdolontha, Rhopcea, Macrophy'la, or Elaphttcera anten- 

 na 1 : not only in the comparative difference in size of club, between fj 1 

 and 9» but also in the more intimate connection between the funicle 

 and club, by a gradual enlargement and unilateral broadening. Further, 

 in this, that the joints modified into the lamellate club vary — Rhopcea to 

 seven, five and three, Macrophylla five and three, Pleocoma seven and 

 four— in different species of the same genus ; and that as in Melolontha, 

 Anoxia, Rhopcea, Rhizolragiis, Lachnodera et al, the lamellate joints are 

 clothed at the edges — the first and last also at its free surface — with stiff 

 bristles. All these are peculiarities, which, partly by themselves, partly 

 in their combination, are characteristic of the Melolonthid antenna. 



Now as the situation of the stigmata in combination with the proved 

 antennal structure, places Pleocoma primarily among the Melolonihidcs, 

 so do other of its characters, as the structure of the mouth, the attenuated 

 tarsi, the dense woolly clothing of the breast, and the free, not connate, 

 ventral segments, point with entire certainty to the particular systematic 

 position which is to be occupied by this genus. By all these characters 

 Pleocoma is referred to the group denominated Leptopodidce by Burmeister, 

 and more particularly to that part of it named Pachypodidce by Erichson. 

 The more comprehensive LeptopodidcB which equal the Tanyproctini and 

 Pachypodidce of Erichson are characterized by Burmeister precisely by the 

 slender tarsi and free ventral segments, ami form in fact an equally natural 

 as well defined group. Within this group appear two modifications in 

 structure of mouth parts: on the one hand normally developed as in 



