257 



HAEEIS TO ZIMMERMAN. 



Cambridge, Nov. 10, 1837. 



You have asked me for the characters of Mr. Sav's new 

 genus Amblycheila, specimens of which are among the insects 

 brought by Mr. Townsend from Oregon and presented by him 

 to the Academy of Natural Sciences of Philadelphia, and now in 

 my keeping. Mr. Say established the genus in a paper printed 

 at (New) Harmony, Indiana, in March, 1830, and reprinted 

 in the Transactions of the Philosophical Society of Philadelphia, 

 N. S., Vol. IV, p. 409 (4to, Philadelphia, 1834). The insect 

 upon which Mr. Say formed this genus, he described in the 

 Journal of the Academy of . Natural Sciences, Philadelphia, 

 Vol. Ill, p. 139, by the name of Manticora cylindriformis ; 

 he obtained it at the foot of the Rocky Mountains, in 

 the expedition under Major Long. As soon as I saw Mr. 

 Townsend' s insects, I thought two of the species must belong 

 to Mr. Say's new genus ; but to make the matter certain, since 

 the receipt of your letter, I have softened them in spirit, and 

 have examined their mouths with great care. [Dr. LeConte 

 states that one of these species is Omus Dejeanii, the other 

 0. Audouinii.~\ The following are the characters in detail 

 which the insects present : — 



Tarsi five-jointed ; legs fitted for running ; anterior tibiae not 

 notched; mouth carnivorous; palpi six ; labials and external 

 maxillaries four-jointed ; maxillse with an articulated hook at 

 the end. 



Genus Amblyeheila Say. 



Head subquadrate, not contracted at base ; eyes small, hemi- 

 spherical. 



Antennce rather slender, filiform, with obconico-cvlindrical 

 joints ; first jeint thickest, about as long as the third ; second 

 joint rather more than half the length of the third ; last joint 

 (eleventh) cylindrical, obtuse at tip. 



Upper lip transverse, very short, anterior edge emarginated, 



OCCAS. PAPERS B. S. N. II. — I. 17 



