G. C. DAVIS. 207 



segment broadly petiolate, strongly arched above and with dorsal carinje ; legs 

 short, compact, femora incrassate ; posterior tibife with a single, large, long, white 

 spur. 



Massachusetts and Toronto, Canada (type, coll. Amer. Ent. Soc). 



AliCOCERUS Foerster. 

 (Synop. der Fam. uud Gatt. der Ich., 1868.) 



The characters given by Foerster in separating the genus are 

 already given in tiie synopsis. To this genus belongs Mr. Cresson's 

 Exochoides coiicinua and mexicana from Mexico, and valida from 

 Cuba. There is but a single known species at present in the U. S. 



Alcocerns frifas^ciatus Cress. {Trijphon), Proc. Ent. Soc. Phil, iii, 276. 



% 9- — 9-10 mm. Black, with the following yellow markings: antennte, palpi, 

 tegulae, scutellums, apical third of first three segments of abdomen, genitalia, 

 more or less of coxae and femora, trochanters, tarsi and tibiae, except tips of pos- 

 terior pair: wings dusky hyaline, nervures brown; head and thorax pilose; 

 antenniB sometimes dusky. 



Three females and two males from Pennsylvania, North Caro- 

 lina and New York (type, coll. Amer. Ent. Soc). 



EXOCHOIDES Cresson. 



(Trans. Amer. Ent. Soc. ii, .37, 1868.) 



This genus is at once separated from Ischyrocnemis Holmgren by 



having the metanotum smooth and shining instead of punctured and 



areolated. It differs also in having the spiracles slit-like instead of 



oval ; otherwise the two genera agree closely. 



Exoclioides texaiius Cress., Trans. Amer. Ent. Soc. iv, 167. 



Ischyrocnemis Carolina Ashm., Pr. U. S. Nat. Mus., xii, 443. 



. — 7-9 mm. Black, with yellow markings as follows : scape, mandibles, palpi, 

 tegulae, line beneath continuing backward under wings and scutellum, line in 

 front on upper margin of prothorax ; prothorax except portion beneath this line, 

 scutellum, metanotum except black transverse line at base, petiole of abdomen 

 except spot between spiracles, apical half of segments two and three, apical third 

 of segments four and five, all of the terminal segment and all of legs, except spot 

 on posterior coxse and inner part of posterior femora; antennse fulvous; all of 

 the yellow markings on the thorax except the tegulse. coxae, posterior femora and 

 base and apex of posterior femora are yellowish ferruginous ; wings hyaline, with 

 a faint dusky spot on the front apical margin, stigma yellow, veins brown ; areolet 

 complete, petiolate; head and thorax pilose. 



Two specimens from Texas and North Carolina (types, coll. Am. 

 Ent. Soc. and U. S. Nat. Mus.) 



CHORIN^IIS Holmgren. 

 (Monograjihia Tryphonidum Sueciae. p. 320, 18.56.) 

 Head transverse ; vertex subtruncate ; face somewhat protuberant ; 

 clypeus not separated. Thorax robust; longitudinal cariuie promi- 



TEANS. AM. ENT. SOC. XXIV. AUGUST. 1897. 



