130 



[August, 



Although the labors of Mulsant have served to establish many natural groups 

 among the species of this difficult tribe, I can by no means agree with him re- 

 garding the generic value of such groups. However constant may be the char- 

 acters used by him, yet they are entirely too unimportant to be used for sepa- 

 rating species, otherwise closely allied. A genus to be natural must differ from 

 its neighbors by some decided modification of structure, accompanied with a re- 

 cojjnizable difference in external form : and although it maybe convenient to give 

 names to subordinate groups, yet they canl n no case be admitted as ger>era. 



For this reason, I find it impossible to adopt Mulsant's numerous genera, and 

 therefore present the following table as showing the relations between such of 

 our native genera, as appear to be really separated by trenchant and recognizable 

 characters. 



Div. I. COCCINELLJE. 



Antennae articulo l^o crasso, Qndo brevi rotundato : tarsi semper dilatati, 

 articulo 3io minuto recepto : palpi maxillares securiformes ; alarum margo 

 simplex. 



A. Mandibulae simplices vel, bifidae. 



1. Antennae longiusculae basi liberce. 



a. Metasterno non diviso, epimeris maiusculis : 



(corpus oblongum.) 



Ungues simplices, tenues 



Uftgues dentati . . . . . . , . 



b. Metasterno diviso, epimeris rainoribus : (cor- 



pus praecipue rotundatum, ungues semper 

 dentati.) 

 Antennae clava lata truncata ..... 

 Antennae clava lata apice rotundata .... 

 Antennae clava elongata : (corpus rotundatum glabrum) 

 Antennae clava elongata, apice emarginata : (corpus 

 oblongum pubescens) 



2. Antennae breves, basi obtectae. 



Labrum occultum . , 



Labrum conspicuum 



3. Antennae brevissimae, basi liberae. ' 



a. Prosternum antice non lobatum. 

 Corpus glabrum, pedes antici dentati . . . 

 Corpus glabrum, pedes mutici, ungues dentati . . 

 Corpus glabrum, pedes mutici, ungues simplices 

 Corpus pubescens, ungues dentati .... 



b. Prosternum antice lobatum, os obtegens 



B. Mandibulae multidentalas ..... 



Anisosticta Chevr- 

 HippoDAMiA Chevr. 



COCCINITLLA Lin. 

 PSYLLOBORA ChcVr. 



Myzia Muls. 



COCCIDULA Kug. 



Chilocokus Leach. 

 ExocHOMus Redt. 



Brachiacantha Chev. 

 Hyperaspis Chevr. 

 OxYNYCHus Lee. 



SCYMNUS Kug. 

 ffiNEIS Muls. 



Epijlachna Chevr, 



Anisosticta Chevr. 



1, A. seriata Lee. Cocc. seriata Mels. Proc. Ac. Nat. Sc. 3, 177. 



NcBmia liiigiosa Muls. 31. 



The genus Nacmia does not seem sufficiently distinct. 



HippoDAMiA Chevr. 



This genus may be divided into two groups : 



at. Ungues omnes acute dentati. {Ilippodamia and Adonia Muls.) 



/8. Ungues omnes obtuse dentati. (Meg-ilia Muls.) 



The following species, except (5), belong to division (.) 



1. H. convergens Guurin : Muls. Cocc. modesta Mels. Proc. Ac. Nat, 

 Sc. 3, 178. 



