.32 NORTHERN ZOOLOGY. 



XV. Genus OMASEUS. Zieg. 



(40) 1. Omaseus orinomum. (Leach.) Mountain Omaseus. 



Omaseus orinomum. Leach. MS, Curtis. Brit. Ent. i, 15. Steph. Illustr. Mandib. i, 114, 3, I. vii, f. 3. 



Length of the body 5J lines. 



Taken frequently in Lat. 54°. and 65°. 



DESCRIPTION. 



Body oblong, glossy, black. Head rather ovate, underneath in some specimens chestnut, in 

 others black ; palpi piceous ; prothorax subcordate rather longer than wide ; a deep, punctured, 

 basilar impression on each side ; posterior margin slightly sinuate ; elytra subacuminate, lightly fur- 

 rowed with from four to six largish impressions in the second and third furrows, the first usually 

 being in the third and the second on the second furrow, but the others occasionally varying ; the 

 natural number of these impressions seems to be five ; legs black with piceous tarsi. 



Variety B. Legs chestnut. 



C. Tibia? and tarsi chestnut. 



From the number of specimens collected in the Expedition I should conjecture this to be one of 

 the most common of North American insects. It appears, however, not to have been noticed by Say, 

 nor was it amongst those collected by Dr. Bigsby in Canada, or by Dr. Mac Culloch and Captain 

 Hall in Nova Scotia. 



(41) 2. Omaseus nigrita. (Curtis.) Negro Omaseus. 



Omaseus Nigrita. Curtis Brit. Ent. i, 15. Steph Must. Mandib. i, 114, 5. 



Carabus Nigrita. Payk. Mon. Car. 79. Fn. Suec. i, 157, 77. Panz. Fn. Germ, xi, 11. 



■ aterrimus. Marsh. Ent. Brit, i, 444, 30. 



Harpalus Nigrita. Gyllenh. Ins. Suec. ii, 88, 8. 

 Platysmus Nigrita. Sturm. Deutsch. Fn. v, G4, 16. 



Length of the body 5^ lines. 



DESCRIPTION. 



Body very black and glossy. Frontal impressions nearly straight ; palpi, scape, and summit of 

 the antenna?, piceous : prothorax subcordate ; rather deeply channelled ; basilar impressions large, 

 punctured, in each are two little abbreviated furrows and a ridge adjoining the margin ; the base 

 itself has a slight sinus; elytra very deeply furrowed, furrows very indistinctly punctured; three 

 minute punctiform impressions in the usual situation, the anterior one adjoining the third and the 

 two posterior ones the second furrow : legs dark piceous : ventral segments of the abdomen minutely 

 wrinkled on each side : on the sides of the breast are some scattered punctures. 



