Deo. 1899.] Dyar: Life-Histories of N. Y. Slug Caterpillars. 249 

 Genus Lithacodes Pack. 



1864. Lithacodes PACKARD, Proc. Ent. Soc. Phil. Ill, 345. 

 1892. Lithacodes Kirby, Cat. Lep. Het. I, 555. 

 . 1894. Tortricidia Neumoegen & Dyar, Journ. N. Y. Ent. Soc. II, 75. 

 "^y^^e., fasciola H.-S. 



This name is given from a resemblance to the Noctuid genus Lith- 

 acodia Hiibn., hence is not preoccupied by it. 



Species: fasciola H.-S. (New York Slug Caterpillars, VH). 

 Genus Heterogenea Knock. 



1793. Heterogenea Knoch, Beitr. Ins. Ill, 60. 



1829. Heterogenea Stephens, 111. Brit. Ent. Haust. II, 84. 



1864. 1 Kroncea Reakirt, Proc. Ent. Soc. Phil. Ill, 441. 



1 87 1. Heterogenea Staudinger, Cat. Lep. Eur. 62. 



1892. Heterogenea KiRBY, Cat. Lep. Het. I, 556. 



1S94. Heterogenea NeumoEGEN & Dyar, Journ. N. Y. Ent. Soc. II, 74. 



Type c rue ill fa Knoch. 



I have not seen Kroncea miniita in nature and Reakirt' s description 

 is not fully reliable. It must, therefore, remain doubtfully placed till 

 more specimens occur. It seems nearest to this genus. 



Species: shurtleffii ^z.Qk. (New York Slug Caterpillars XVII), 

 ? miniita Reak. 



Considerations Suggested by Geographical Distribution. 



It is impossible to go into this subject fully at present as none of 

 the exotic species are known in all of their stages, so I am not sure of 

 the exact extent of the groups. However a few suggestive points appear. 



The best marked group of Eucleids, geographically, is that which I 

 have called the " palcearctic smooth Eucleids" (Psyche, VIII, 172). 

 They are distributed in northern North America, Europe and Asia, 

 reaching northern India. Only one species reaches South America 

 (^Lithacodes fasciola), but this is not a southern species, strictly speak- 

 ing, for it extends as far north as any species of the family. The 

 species of Apoda recorded in Kirby's catalogue from South Africa, 

 East Indies and South America probably do not belong to this group. 

 All of them about which there is any recent information have proved 

 to belong in other genera. This group of Eucleids seems correlated 

 with the former arctic continent which extended across the Atlantic, 

 from the Jurassic to the Eocene times and was always more or less dis- 

 tinctly separated from the equatorial land (see Plates VIl-VIII).* 



* I am indebted to Professors H. F. Osborn and G. Van Ingen, of Columbia 

 Lfniversity, for information in the preparation of these maps. 



