96 TRANS. ST. LOUIS ACAD. SCIENCE. 



eyes by f of their shorter diameter. Face, orbits reaching to the occiput 

 where they are dilated into a triangular spot, clypeus, mandibles except 

 their tips, palpi and cheeks half way up the eye, all yellowish white. 

 Antennre brown-black, with joint i whitish beneath, f as long as the body, 

 ist joint of flagellum 2-i times as long as wide, 2d and following joints 

 about ij times as long as wide. Thorax subpolished, with distinct, rather 

 close, shallow, fine punctures, much less distinct and close on the pleura 

 and sternum. Metathorax without a trace of any carinas. Tegulae, a 

 broad line underlying the humeral suture nearly to its tip, and the lower 

 face of the mesosternum, all whitish. The lateral and anterior margin of 

 the mesonotum, and the region surrounding the two scutels, black. Abdo- 

 men i longer than the head and thorax together, subpolished, with rather 

 close, fine, shallow punctures, obsolete on the tips of the joints. Joint i 

 squarely truncate at base with the angles acute, £ longer than wide, £ 

 wider behind than before, its 2 carina? only reaching J of the way to the 

 tip ; its anterior angles, and the lateral carina nearly to its tip, black. Joints 

 7 and 8 black. Four front legs whitish, with the 4 femora (except the knees) 

 and the outer face of the middle tibiae, pale rufous. Hind legs pale rufous, 

 with the tips of the coxae, and the entire trochanters, spurs and tarsi, 

 whitish ; extreme tips of the femora, of the tibiae and of the tarsal joints, 

 obfuscated. Wings subhyaline ; veins and stigma black. Length $ .24 

 inch. Front wing $ .18 inch. 



One <? ; $ unknown to me. Distinct by its rufous abdomen, 

 etc., from any of Mr. Cresso'n's species. 



ExocllUS albiceps, n. sp.—^.— Differs from the above only as follows : 

 1. The head is white, except a black spot just enclosing the ocelli and a 

 large lunate black spot on the occiput, medially confluent with the other 

 one by a short space. Face, except the orbits, tinged with rufous. 2. The 

 ist joint of the flagellum is only twice as long as wide, the 2d only \ longer 

 than wide, and the following joints square. 3. The thorax is glabrous and 

 polished, and the carinae on the metathorax are all distinct as in albifrons. 

 The white markings are rufescent and less distinct, and the only black 

 markings are a short line inside the origin of the front wing, an indistinct 

 vitta on the disk of the lateral lobe of the mesonotum, and a large spot at 

 the tip of its middle lobe. 4. The first joint of the abdomen is immacu- 

 late, \ longer than wide, and twice as wide behind as before, its 2 carinae 

 reaching half way to the tip. An obtrigonate, dorsal spot at the tip of 

 joint 5, and the whole of 6-8, black. 5. The legs are all dull luteous, with 

 an abbreviated, exterior vitta on each femur, and an unabbreviated one 

 on each tibia. Length 0* «l8 inch. Front wing d 1 -*5 inch- 

 One o* ; $ unknown to me. Distinct from all Mr. Cresson's 

 species by its rufous abdomen, etc. 



EXOCHISCUS, new genus. 

 Head with the face and cheeks prominent (as in Exochus). 

 Antennae short and robust, subgeniculate ; the ist joint very long, 



