12 U.S. NATIONAL MUSEUM BULLETIN 290 



Snowi group: cribripennis Leconte, simulans Schaeffer, snowi Schaeffer. 



With seven rows of punctures and an incomplete row between 

 fifth and sixth rows, punctures often large and sparse; basic elytra! 

 dark markings consisting of vittae on intervals two, four, and six 

 (latter formed of two united intervals) ; anterior margin of prosternum 

 of both sexes produced into a broad, often pointed lobe; pronotum 

 predominantly dark, with oblique, basal, yellowish markings, lateral 

 and apical markings yellowish; size large. 



Confluentus group: alternans Suffrian, brunneovittatus Schaeffer, cerinus B. E. 

 White, confluentus Saj'', defectus Leconte, dorsatus, new species, fulguratus Leconte, 

 luteolus Newman, pumilus Haldeman, spurcus Leconte. 



Basic elytral pattern of dark markings consisting of complete 

 vittae on intervals two, four, and six (latter formed by union of two 

 intervals) often with pattern modified or absent; v/ith seven rows of 

 fine, distinct punctures, usually also with a short series behind hu- 

 merus; anterior margin of prosternum of male usually produced 

 ventrally into a pointed lobe, sometimes evenly arcuate, that of 

 female sometimes produced into a lobe, often evenly arcuate; pronotum 

 often with disk dark and with a vague pattern; size small to medium. 



Specimens which differ in minor details of color and elytral puncta- 

 tion may be distinguished within this group of species and subspecies. 

 The taxa within the complex are so close and ill-defined that the 

 arrangement advanced here can be considered only tentative. I have 

 found it impossible to delimit to my satisfaction the apparently un- 

 described taxa on the basis of external morphology alone and feel 

 that a complete understanding of the interrelationships will probably 

 have to await biological studies. Whether a given series of apparently 

 similar individuals (including some described taxa) is to be considered 

 a species or subspecies (and, if the latter, to which species it is allied) 

 appears to be largely conjectural. Those taxa I have described are 

 the ones most obviously distinct; others are not treated herein because 

 of the diffi^culties. 



The only species not assigned to any of the above groups is fri- 

 zonatus Suffrian. I believe it properly belongs to a separate group that 

 would include it and at least four other species from Central America 

 with similar coloration. In the USNIVI collection, four and possibly 

 five species are similar to trizonatus; of these, many have been deter- 

 mined as trizonatus but are clearly distinct from it. 



Schaeffer's types — It is sometimes quite difficult to determine 

 with certainty whether specimens in the USNM that have been 

 accepted as Schaeffer co types or paratypes do actually represent types, 

 or if|certain specimens that have not been accepted as types should 

 now be so labeled. Evidently all types of Cryptocephalus species and 



