456 SUBFAMILY X. CURCULIOXIXJK. 



which are subaquatic in habits, feeding mainly upon plants of the 

 genus Liidwigia. 



KEY TO SPECIES OF PERIGASTER. 



o. Dorsal channel of thorax impressed only at base; elytra not mottled 

 with white. 709. CRETURA. 



aa. Dorsal channel entire but feeble; elytra mottled with white. 



710. OBSCUBA. 



709 (8861). PERIGASTER CRETURA Herbst, 1797, 70. 



Broadly oval. Brownish-black, very thinly clothed above with small 

 pale or brownish scales; beneath densely clothed with pale brownish-yellow 

 scales, the last three segments less densely scaly; antennae and legs reddish- 

 brown. Head broadly impressed between the eyes; beak subcarinate, punc- 

 tured, pubescent, as long as the head. Thorax one-half wider than long, 

 lateral tubercles acute, disc finely and densely punctured. Elytra with 

 sides broadly rounded, feebly converging behind; striae rather deep, wide, 

 punctured; intervals densely and finely rugose, feebly convex. Length 

 2.73 mm. 



Lake and Dubois counties, Ind., scarce, probably throughout 

 the State. May 12 Sept. 19 ; from flowers of golden-rod on the 

 latter date. Caldwell, X. J. ; Flatbush and Rockaway, X. Y., 

 June 20 July. Black Mountains, X. C., June July. Dunedin, 

 Fla., Jan. 24 Mch. 22. Ranges from Ontario and Xew England 

 to Michigan and Iowa, south to Florida and Texas. Pierce (1916) 

 states that in Texas it breeds externally on the leaves and stems 

 of Lntlicif/ia tuitans Ell. The larvae are yellow and have a gliding 

 motion. They spin a silken thread with which they form a cover- 

 ing while they eat. working mainly under water. The pupal cell 

 is composed of silk and a dark substance impervious to water. 

 The adult is saltatorial. 



710 (8862). PERIGASTER OBSCURA Lee., 1876, 283. 



Resembles cretura in form but slightly smaller. Reddish-brown to 

 piceous; elytra with a small but conspicuous white spot in front of middle 

 on third interval, another near apex and smaller ones scattered irregular- 

 ly on sides; antennae and legs paler reddish-brown. Head strongly punc- 

 tured, concave. Beak very stout, as long as head, finely punctate. Thorax 

 more coarsely punctured than in cretura, each puncture bearing a small 

 yellowish scale. Striae of elytra deeper, more closely punctured; intervals 

 distinctly more convex. Length 2.5 2.8 mm. 



Dunedin, Enterprise and Lake Istokpoga, Fla., Jan. 19 Dec. 

 28. Frequent in winter beneath boards along the border of 

 ponds and lakes. Recorded only from Georgia and Florida. 



