ROLAND HAYWARD. 191 



A STUDY OF THE SPECIES OF TACHYS OF 

 BOREAL AMERICA. 



BY ROLAND HAYWARD. 



Probably few, if any, genera of Carabidse have received so little 

 attention from collectors and students of our fauna as the one which 

 forms the subject of the present essay. This is due in part to the 

 small size of the species composing it, and also to the scattered and 

 fragmentary condition of the literature of the subject. 



The nearest approach to a monograph of our species that has ever 

 been published is contained in Dr. LeConte's " Descriptive Cata- 

 logue of the Geodephagous Coleoptera Inhabiting the United States 

 east of the Rocky Mts."* In a paper which appeared a few years 

 later f the views therein expressed were further modified by that 

 author, several new species described and the genus Pericompsus 

 erected for the reception of ephipjnatus, sellatus and Icetulus. Since 

 that time scarcely anything has been published in this country, with 

 the exception of a few isolated descriptions of new species. With 

 regard to the foreign works on the subject, there are two which 

 require especial mention. The first of these, " De Bembidiis Euro- 

 pseis," was published by Jacquelin -Duval, in 1851. % Tuchys is 

 therein regarded as a group of Benibidium, but several characters 

 are suggested in Duval's monograph which have been of service in 

 the separation of our species. The second is by Motschultsky,|| and 

 contains a subdivision of the genus into six genera, the characters 

 on which they are based being of little or no value, as regards our 

 species, even for the definition of groups. The work is so inacces- 

 sible to the majority of our students, however, that a reprint of the 

 table of genera therein contained is published in the appendix, 

 together with the original descriptions of the species described from 

 North America, which I have as yet been unable to identify. 



Some months after the publication of my paper on Bembidium, 

 I undertook to arrange the species of Tachys in my own cabinet. 

 This was done without any intention of publication, but it soon 



* Ann. Lye, 1848, iv, pp. 468-473. 

 t Ibid, 1851-2, v, pp. 191-194. 

 X Ann. Sex-.. Ent. France, 1851, ser. 2, ix. 

 || Etudes Ent.. 1862. xi, pp. 24-37. 



TRANS. AM. ENT. SOC. XXVI. JANUARY, 1900. 



