Sept., 1912.] Matheson : Haliplid;e of North America. 169 



Abdominal segments shining, sparsely punctate. Posterior coxa pvTnctate, 

 attaining the fourth segment of the abdomen. 



Elytra each with ten rows of large shallow punctures, intervals each with 

 a definite row of small punctures ; apices of elytra obliquely truncate 

 (Plate V). 



Described from one specimen (female) from the Pacific Slope. 

 Type. — In the Entomological Collection of Cornell University- 

 Ithaca, N. Y. 



Haliplus ruficoUis DeGeer. 



Dytiscus ruficoUis DeGeer. Memoires, IV, 1774, p. 404. 



Dytiscus impressus Fabricius. Mant. Ins., I, 1787, p. 193. 



Haliplus immaculicollis Harris. New England Farmer, VII, 1828, p. 164. 



Haliplus americanus Aube. Species des Col., VI, 1838, p. 26. 



General color rufous to reddish-yellow with black spots and markings on 

 elytra. Length 2.5-3 mm. 



Head rufous, slightly infuscate behind; punctate; eyes broadly oval; 

 labrum slightly emarginate, a row of setae on its anterior margin ; antennae 

 testaceous. 



Thorax rufous ; pronotum punctate, punctures of same color as pronotum, 

 less densely punctate on sides and front ; disc sparsely punctate ; paired basal 

 impressions present, never as long as one third the length of the pronotum ; 

 prosternal ridge grooved, convex longitudinally, steeply declivous in front; 

 sides constricted in region of prothoracic legs, not widening anteriorly ; 

 abdominal segments smooth, shining, each except the last, with a series of 

 punctures near posterior margin ; last segment triangular in outline, punctate. 

 Legs rufous ; posterior coxae punctate, reaching the fourth segment of the 

 abdomen. 



Elytra with ten rows of punctures, the outer two rows of same color as 

 elytra, the remainder black ; intervals with irregularly placed punctures ; 

 black spots and margins distributed as shown in Plate XV. There is con- 

 siderable variation in the arrangement and extent of the black markings. 

 Apical margins of elytra rounded, not sinuate. 



Habitat. — Common probably all over Xorth America. 



Haliplus triopsis Say. 



Halipus triopsis Say. Trans. Amer. Phil. Soc. II, 1825, p. 106. 

 Haliplus pantherinus Aube. Species des Col. VI, 1838, p. 29. 



General color pale yellow to reddish-yellow with black markings on 

 pronotum and elytra. Length 3.75—4.25 mm. 



Head punctate except a small area on the middle of vertex ; eyes circular 

 in outline ; labrum slightly emarginate, a row of setae on the anterior margin, 

 rounded at the sides ; antennae reddish-yellow to pale yellow. 



Thorax pale yellow ; pronotum with an oval black spot on its anterior 



