82 PROCEEDINGS OF THE NATIONAL MUSEUM vol. m 



Psammodius oregonensis Cartwright 



Figures 9, 37, 38, 50, 66, 72, 87 



Material examined: Forty-four third-stage larva collected in 

 sand dunes under grass roots at Waldport, Oreg. Four were collect- 

 ed on Jan. 29, 1955; 10 on Mar. 29, 1955; 20 on June 16, 1955; and 

 10 on Mar. 22, 1957. 



Description: Maximum width of head capsule of third-stage larva 

 0.79-0.86 mm. Cranium whitish yellow, surface smooth. Five or six 

 dorsoepicranial setae and two microsensillae on each side. Each 

 antennal base with two long setae and two short setae exterolaterally 

 and one long seta dorsally. 



Epipharynx slightly broader than long. Protophoba bistichous on 

 left and monostichous on right with 12-14 microsensillae. Crepide 

 subcircular. 



Dorsal annulets of abdominal segments 1-5 with setation as follows: 

 each prescutum with eight short setae, each scutum with six long 

 setae and 12 short setae on each side, and each scutellum mth 12 short 

 setae. 



Raster with teges of 36-44 hamate setae scattered irregularly on 

 the venter of 10th abdominal segment, five or six long slender setae 

 on either side. 



Psammodius hydropicus Horn 



Material examined: One third-stage larva collected in field, with 

 adults, at Folly Beach, S.C., June 14, 1941, by O. L. Cartwright 

 (USNM). 



Description: Maximum width of head capsule of third-stage larva 

 0.66 mm. Cranium light j^ellow, surface smooth except for two de- 

 pressions on each side on the frons. Five or six dorsoepicranial setae 

 and two microsensillae on each side. Each antennal base with two 

 long setae and one short seta exterolaterally and one long seta 

 dorsally. 



Epipharynx with protophoba bistichous on left and monostichous 

 on right; protophoba with 12 microsensillae. 



Dorsal annulets of abdominal segments 1-5 with setation as follows; 

 each prescutum with eight short setae, each scutum with five long 

 setae and 11 short setae on each side, and each scutellum with 12 short 

 setae. Raster with teges of 33 hamate setae curved at their distal 

 ends. 



Genus Pleurophorus Mulsant 



Larvae of genus Pleurophorus may be characterized as follows: 

 Each antennal base with two long setae and a short seta extero- 



