ROLAND HAYWARD. 35 



Looking at Bembidmm from the standpoint of an evolutionist, I 

 have been led to believe that it is decidedly a modern ggnus, or at 

 least one that has undergone much modification during geologically 

 recent times. The fact that so many futile attempts have been made 

 at its subdivision points, I think, to this conclusion. There is indeed 

 a certain lack of fixity in many characters which indicates strongly 

 the recent nature of their development. As regards the distribution 

 of the species, although many extend over an immense amount of 

 territory, we find that some groups, and usually such as possess some 

 peculiar or anomalous character, are confined to cer ain regions, as 

 for instance that containing scudderi, henshaivi, etc. The above 

 remarks seem to be applicable to the Bembidiini as a whole. From 

 the other Carabidae this tribe is distinguishable by its subulate palpi, 

 a character in itself peculiar, while the genera are separable by 

 rather feeble characters, some as for instance Tachijpus and Peri- 

 compsus, by such as are usually used rather for the separation of 

 groups of species than of genera. With regard to the palajonto- 

 logical history of the genus, Mr. S. H. Scudder informs me that it 

 is unknown earlier than the tertiary period,* when the insect fauna 

 was nearly the same as that of the present day. But I have neither 

 time nor space to discuss this subject further. I merely wish to call 

 attention to an interesting subject for investigation. 



The preparation of this paper has taken a very large amount of 

 time, and I have had many difficulties to contend with. Should it 

 prove of use to the student of our fauna, however, and assist in 

 clearing up the confusion which exists with regard to this genus, I 

 shall feel amply repaid for all my work. As will be observed, I 

 have not attempted to identify all of the species that have been de- 

 scribed from North America, as the types of those that remain uni- 

 dentified are probably in European collections. Synoptic tables and 

 descriptions have been prepared of the species known to me in nature, 

 and the original descriptions of those that remain unrecognized are 

 reprinted in the appendix, in order to assist those who have not ac- 



'■■■ I learn from Mr. Scudder that seventeen fossil species have heen found. Of 

 these five existing species have heen recorded from the Pleistocene of Gallicia. 

 Bavaria and France, and five more extinct one from Ohio, Canada, France and 

 Gallicia. Seven species are known from the older tertiaries (including two un- 

 published species from Florissant. Col.). These are from Radoboj, Aix. amher 

 and Colorado (Florissant). The genus has also been recognized in Alsatia and at 

 Oeningen, in Baden. 



TRANS. AM. ENT. SOC. XXIV. FEBRUARY, 1897. 



