278 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lo* 



fulgidus Motschulsky, which occurs in Turkey. However, the resem- 

 blance is only in size and general shape, there being no indication of 

 close relationship with vernalis or other species. This conclusion 

 was also reached by Boucomont (1911, p. 345), who compares 

 Peltotrupes with the oriental subgenus Thorectes. 



The genus Peltotrupes presents an interesting taxonomic problem, 

 due in part to the following causes. The species range almost 

 entirely across Florida from near Tampa northward to the vicinity 

 of Lake City; however, their distribution is very spotty. Young 

 (1950, p. 88) states that their "rarity seems to be due to the restricted 

 habitat[s] of the species and to [their] occurrence in the winter and 

 early spring months." The habitat is St. Lucie and other deep sands 

 covered with scrub oaks and pine but without much ground cover. 

 The members of the genus appear to be deep burrowing (Howden, 

 1952, p. 42), placing their larval cells at some depth in the sands. 

 The necessary sand ridges are nregularly scattered over northern 

 Florida, some of them isolated by swamps or lowlands. Furthermore, 

 there are the short winter period of adult activity and the insects' 

 very doubtful powers of flight — I spent some time trying unsuccess- 

 fully to induce beetles to fly. Because of these facts, I distinguish 

 between several rather distinct, isolated populations. 



The development of distinct populations of isolated colonial 

 beetles was early noted in the related genus Pleocoma, in which the 

 females are flightless. Linsley (1946, p. 61) states: "There is little 

 doubt that the various forms of Pleocoma to which names have thus 

 far been applied represent distinct populations, but the exact taxo- 

 nomic status of the more closely related of these must await future 

 interpretation on the basis of longer series of both sexes from many 

 more geographical areas than are now represented in collections." 

 This last statement is equally applicable to the populations of 

 Peltotrupes. 



Isolation of the various populations appears to have occurred in 

 recent geological times, as the populations, while distinct, are very 

 close structurally. The male genital armature is very complex but 

 is also quite variable, and a method of separation of the populations 

 by constant genitalic characteristics was not found. 



Descriptions have been based on examples that I believe are 

 typical of the different populations. Care must be taken with worn 

 specimens which before collection have burrowed sufficiently to 

 obliterate some of the better distinguishing characteristics. 



Characteristics distinguishing the larvae from known larvae of 

 Geotrupes (Howden, 1952, p. 48) are: Greatly shortened third antennal 

 segment, presence of tuberculate bases of the setae on the end of the 

 tibiotarsus, the shape of the anal lobes, and the greatly swollen 



