NO. II LARVAE OF THE ELATERID BEETLES GLEN I93 



Brown has done much toward estabhshing the natural affinities 

 of many of the species now included in the genus. However, no 

 proposals have yet been made for reducing the genus to a more homo- 

 geneous assemblage. The larval record is much too incomplete to 

 form a basis for sound revision. In fact, since only lo percent of the 

 species are known in the larval stage, it is dangerous even to attempt 

 an appraisal of specific relationships. However, a brief appraisal of 

 the larval evidence is presented with the hope that it might encourage 

 further efforts in this direction. 



The 44 species of Liidius studied have been arranged into 17 dis- 

 tinct "species groups," some groups being represented by a single 

 species. For purposes of identification, these groups are best con- 

 sidered in the four major sections (I, H, HI, IV) shown on page 191. 

 However, the natural affinities ot Ludius sjaelandicits (Miiller) are 

 believed to lie nearer to several species in section HI than to the 

 other species in section I. Within section II some of the "species 

 groups" are very closely related, e.g., inflatns and aeripennis, semivit- 

 tatus and edwardsi; whereas propola, trinndulatits, and fallax are not 

 quite so closely allied ; and hipustidatus, rotundicolUs, and nitididus 

 are relatively isolated. In contrast, the Ludius species that fall in 

 section III are not more closely related to one another than are the 

 recognized genera Elathous, Limonius, Athous (pars), and Leptii- 

 roidcs, which also fall in that section. 



The larval characters suggest that for taxonomic purposes the 

 genus Ludius might be revised by making the following subdivisions 

 (genera ?) : 



Subdivision i : the ctipreus and apprcssus groups ; the relationships of appressus 



(Randall) seem to lie with cupreus. 

 Subdivision 2 : all Ludius included in section II ; the nitididus group might 



form the nucleus of a distinct subdivision connecting with the genera 



Cryptohypnus and Crepidomenits. 

 Subdivision 3: L. divaricatns (LeConte) and its allies; this is an isolated 



species without close affinities to any known group in the Lepturoidini. 

 Subdivision 4: L. sjaelandicits (Miiller) and allied species, if any exist. 

 Subdivision S : the pyrrhos group. 

 Subdivision 6: the limoiiiifor}iiis group. 

 Subdivision 7: L. rcsplendcns (Eschscholtz) and its allies; the possibility of 



removing resplendcns to the genus Elathous warrants consideration. 



Subdivisions 4 and 5 have a somewhat common bond in the unusual 

 condition of the spiracles in the eighth abdominal segment, and in setal 

 and sculptural characters. Likewise, subdivisions 4, 5, 6, and 7 all have 

 the urogomphal prongs subequal and certain other characters in 



