230 



the genera of Elaters in Dejean's Catalogue were founded, and 

 in many cases, I drew out the characters in detail, and still 

 have tliem by me in manuscript. At that time I concluded 

 that the two species above named could not both be included in 

 Adrastus ; but which of the two was to be regarded as the true 

 type I could not tell, and therefore made my OAvn election, 

 adopting the quadrimaeulatus as the European type. If, how- 

 ever, the limhatus be the true type, I suppose you or somebody 

 will have to make a new (sub-) genus for the quadrimaeulatus 

 of Fabricius. 



I append some of the characteristics of five closely allied 

 species of Agonum (or Platynus Lee), of black color, etc., 

 arranged in a table : — 



A. Fifth elytral stria not dilated behind. 



a. Two impressed points on the third, and one on the second stria. 

 * Sides of the thorax regularly curved. 



t Thorax broad. Tibiae and tarsi black . .1770 melanarium^ ? Dej. 

 tj- Thorax narrow. Tibise and tarsi rufous . 61 politulimr Hentz. 

 ** Sides of the thorax somewhat angulated .1771 nitidum Harr. MS. 



b. Impressed points irregularly disposed; one 



impressed point on the third stria, one on 

 the interval between the second and third 

 stria, and the third on the second stria, 

 or on the third interval 1525 collare Say, ined. 



B. Fifth elytral stria dilated behind, one im- 



pressed point on the third stria, and the . ..^ ^^ , 



, , T . ,„. ^ { Harnsii LeLonte. 



other two on the second stria 1772^ 



( sulcatum UaiT. MS. 



HARRIS TO LECONTE. 



Cambridge, Nov. 24, 1853. 



The insect you have sent me as the '•'■Elater eollaris Say, 

 verus'' seems to me to be a variety of Say's E. ruhricuSy 

 with an immaculate thorax. Say's description is faulty, be- 



1 Dr. LeConte thinks this a mere variety of 1772. 



2 melanarium Dej. (to Dr. LeCoute). 



