NATURAL SCIENCES OF PHILADELPHIA. 387 



The 9 differs from the tf in the thorax heing always marked with obscure 

 green, Dot blue, the pleura exhibiting the same reflections as in one <$ ; in 

 the abdomen being more robust and of an obscure green, not blue ; and in the 

 obhastiform spots on joints 2 7 being of a decided metallic green and cover- 

 ing the full length of every joint, the acute tip of each spot being partly 

 truncate ; joints 8 9 are black above, except a narrow basal line. The pte- 

 rostigma also is pale-brown, not black. The appendages are pale, short and 

 conical, the superiors rather the longest, the inferiors directed upwards ; and 

 there is a long acute spine at the tip of the eighth ventral segment. The 

 whole body beneath, including the legs, is more or less pruinose. Postcubi- 

 tals 1011. 



Length ^ 2930 mill. 9 27 mill. Alar expanse r? 3435 mill. 9 34 

 mill. Two rf, one $ ; one pair taken in coitu. Specimens of this insect 

 were sent by me in 1860 to Dr. Hagen, who pronounced it a new species, and 

 will probably name it in his forthcoming Appendix to the Synopsis. It 

 scarcely differs from Agr. Doubledayi, Selys, except in the apex of the supe- 

 rior tf appendages being not excised. The style of ornamentation is precisely 

 that of Ayr. civile, and varies similarly in $ 9 It is our commonest spe- 

 cies at Rock Island, except perhaps Agr. Ramburii. 



Agkion binotatum. n. s. $ Brassy black. Head and thorax villous. 

 Front pale reddish brown, reddish brown, or in the living mature insect purple, 

 fading to reddish brown in death ; transverse stria of front except laterally, a 

 transverse line before the anterior ocellus, and another divaricating from the 

 base of the antenna to a point before and behind the posterior ocellus, black ; 

 antennae black, their basal joint the color of the front ; all behind the ocelli, 

 as well as the region of the ocelli, black, the occiput with a transverse line, 

 and on each side with a triangular brown spot, both of them subobsolete. 

 Posterior prothoracic lobe rounded ; dorsum of thorax colored as the front, 

 with a narrow dorsal black stripe ; pleura reddish white, often pruinose, with a 

 broad humeral stripe generally enclosing above a pale spot or short stripe, a 

 a short line under the front wing, and a long narrow stripe in the medial 

 suture, stouter above, all black. Abdomen with a yellowish dorsal line on 

 joint 1 4, shorter and narrower in each successive joint ; joints 1 4 or 1 6 

 laterally yellowish, more indistinctly in each successive joint ; a conspicuous 

 yellowish basal annulus on joints 3 6, less obvious oh 7 ; joints 9 and 10 

 blue, except on the lateral margin, 9 with a black medial dot on each side 

 the dorsum ; joint 10 triangularly emarginate at tip, with a pale tubercle 

 under each salient angle ; venter black. Abdominal appendages black ; the 

 superiors short, moderately robust, somewhat tapering, with a large, robust, 

 glabrous tubercle nearly as long as the appendage on their lower inside corner ; 

 the inferiors longer, vertically very wide, not tapering, widely emarginate 

 and terminating in two obtuse divaricate teeth, the lower one shorter. Legs 

 black ; tibiae superiorly yellowish. Wings subfumose ; pterostigma brown, 

 paler on its margins. Postcubitals 13 17. 



The 9 differs in the coloring being paler, and the markings of the hind 

 part of the head distinct ; the spot or stripe enclosed by the humeral black 

 vitta is larger, and often confluent with the pale color behind ; the sides 

 of abdominal joints 1 4 or 1 6 are more distinctly yellowish, and joint 9 is 

 only blue at tip, sometimes also with a dorsal and lateral blue spot ; no ven- 

 tral spine. The femora are luteous, blackish only superiorly and towards 

 their tips, and the tibiae are entirely yellowish, blackish only on their inferior 

 base. Postcubitals 15 18. 



Length J 3638 mill. $ 3537 mill. Expanse $ 4549 mill. $ 4951 

 mill. Four $, five $ . Occurs on and near Wisconsin log-rafts. Very near 

 Agr. fumipenne, Rambur, but differs in the tf femora being entirely black, and 

 the abdominal joints 9 and 10 $ 9 partly blue, and also in the shape of the 

 superior tf anal appendages. Is related also to the Mexican species Agr. 

 calidum, Hagen and Agr. cupreum, Hagen. 



1862.] 



