48 



tlironghoiit, somewhat more coarsely so than in P. palllpes. The 

 dorsal outline of the metascutellum is concave, the metathorax 

 being nearly truncate posteriorly, owing to a tuberosity projecting 

 from its uppei* posterior part. Metascutellum not margined or 

 carinate. Antennte eleven (thirteen) jointed, joints distinct except the 

 third and the last three. In the female the first joint is pale yel- 

 low, the second dark fuscous, and the remaining joints black. All 

 but the first thickly black pubescent, those beyond the second 

 having each a circlet of long appressed hairs. 



In the male the antennae are pale yellow throughout, similar in 

 appearance to those of the female, but with the last two joints 

 closely united, forming a compact ovate club. In both sexes two 

 minute sub-joints occur between the second and third jomts. Wings 

 in all the specimens seen rudimentary, legs pale, the coxae, femora 

 and upper half of the tibiae, tawny yellow, the remainder of the leg 

 being pale yellow, except the tip of the tarsus, which is dusky. 

 Abdomen smooth, blue black above, lightening into piceous beneath, 

 ovate, acute, in the female ; smaller, obtuse, and more nearly oval in 

 the male. 



Total length 2.12 mm. ; head, .7 mm. wide ; thorax, .45 mm. ; abdo- 

 men of female, .62 mm. by 1.05 mm. ; antennae, .82 mm. 



This species appeared in our breeding cages of the Hessian fly 

 during the months of June, July and August, in 1883 and 1884. 

 Flaxseeds collected August 7, 1883, at DuQuoin, from stubble in 

 the field, yielded the parasite August 17 ; parasites emerged June 

 21 from flaxseeds collected at Marshall on the 21st of May; those 

 obtained at Robinson, in Clark county, May 25, emerged from the 

 flaxseed June 20 ; and others obtained at Eobinson, June 14, gave 

 the parasites July 10. 



Tetrastichus carinatns, n. s. 



A slender, smooth, dark steel-blue species, 2 mm. in length, with 

 pale legs, four- jointed tarsi and eight- jointed antennae. 



The head is very short, not wider than the somewhat slender 

 thorax, impunctured, as are also the thorax and abdomen. Eyes 

 large, dark red, broadly elliptical, occupying the whole longitudinal 

 diameter of the head and even encroaching upon its posterior sur- 

 face. Front broadly bisulcate for the reception of the scapes of the 

 antennae. Antennae short, eight-jointed, joints very distinct, except 

 those of the ovate club, (three in number), which are very closely 

 compacted. Second joint shorter than the third, which is longer 

 than fourth and fifth, these being subequal. I'irst and second joints 

 of the club nearly equal, thicker than the preceding. Flagellum of 

 the antennae pale, provided with a few erect black hairs, and long 

 appressed yellow ones. 



Prothorax is very short ; the mesoscutum very long, narrowing 

 posteriorly, when it is broadly truncate against the scutellum, regu- 

 larly convex, minutely carinate longitudinally on the middle line ; 

 parapsidal grooves complete. Scutellum vaulted, with two longitud- 

 inal carinae. Abdomen of female pointed ovate, broadest in front 

 of the middle, somewhat flattened above. 



