160 Journal New York Entomological Society. [Voi.vn. 



species, and may prove to have full generic value. In Diomus the 

 prosternal carina; are as distinctive and charcteristic a feature as in 

 Pullus or Scymnus proper, and they are by no means obsolete as 

 stated by Dr. Horn ; they are, however, finer and less visible under 

 low powers of amplification. In this group, which is .indeed almost 

 entitled to generic rank, the first ventral suture is generally more 

 obliterated toward the middle than in the others. The separation of 

 Scymnodes Blackb. , from Scymnus, upon this character, would not be 

 warranted even if the line of demarkation could be distinctly drawn. 

 In the old world, Scymnus proper seems to be about as abundant as 

 Pullus, but in America the disparity in numbers is very great, the 

 former being relatively very feebly represented. 



Scymnus punctum of LeConte, which is closely allied to the Euro- 

 pean////^/////////, belongs to the genus Stethorus of Weise, very distinct 

 on account of the deflexed presternum; it is in no way related to nanus, 

 with which it is compared by Dr. Horn. 



The following species are omitted from the table because of un- 

 certainty regarding their true position. 



S. brullei Muls. — Oval-oblong; elytra black, "each with a rounded red spot in 

 apical third. Length 3.1 mm.; width 1. 5 mm. Florida. May be placed 

 before hemorrhous but the proportional elongation is much greater. 



S. puncticollis Lee. — Broadly oval, black, the head and prothorax finely and 

 densely punctured, the latter with a small yellow spot at the apical angles ; 

 elytra densely punctate, with a narrow testaceous apical margin; legs pale, 

 the femora piceous. Length 2.25 mm. Upper Mississippi. May be placed 

 just before agricola in the table. 



S. abbreviatus Lee. — Black throughout, the legs rufo-piceous ; prothorax sparsely 

 punctured, densely toward the sides ; elytra densely and coarsely punctured, 

 the metacoxal plates three-fifths as long as the segment. Length 2. 1 mm. 

 Lake Superior (Eagle Harbor). To be placed immediately after weidti in the 

 table. 



S. flebilis Horn — May be inserted just before nubes in the table 



S. opaculus Horn— May be placed just after circumspectus. 



S. bisignatus Horn — To be inserted immediately after bivulnerus. 



S. amabilis Lee. — To be placed just before guttata tus. 



S. xantJiaspis Muls. — Should appea'r immediately before houstoni. 



S. icteratus and cyanescens of Mulsant, cannot be placed, and the atramentarius 

 and infuscatus of Boheman, cannot be certainly identified. 



Cephaloscymnus Crotch. 

 The two species thus far discovered are mutually closely allied, but 

 differ in color and sculpture. The Cephaloscymnus ornatus of Horn, 



