230 



the genera of Elaters in Dejean's Catalogue were founded, n.id 

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

 have them 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 own election, 

 adopting the quadrimaculatus as the Eui'opean type. If, how- 

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

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

 of Fabricius. 



I append some of the characteristics of five closely allied 

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

 arrano;ed in a table : — 



A. Fifth elytral stria not dilated beliind. 



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

 * Sides of the thorax regularly curved. 



•j- Thorax broad. Tibiaj and tarsi black . .1770 melanarium^ ? Dej. 

 fj- Thorax narrow. Tibiaa and tarsi rufous . 61 polilidum" 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 dilatefl behind, one im- 



pressed point on the third stria, and the 

 ., , ., J i- , „^o 1 -"<"''*'*''"LeConte. 



other two on the second stria It t2-{ 



( sulcatum HaiT. M8. 



HARmS TO LECONTE. 



Cambridge, Nov. 24, 1853. 



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

 ven*s" seems to me to be a variety of Say's E. i'id)ricus^ 

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



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



2 vidanarium Dej. (to Dr. LcConte). 



