OF SOME NEW AND INTERESTING SPECIES OF WATER 

 BEETLES OF THE FAMILY GYRINIDAE IN THE 

 UNITED STATES NATIONAL MUSEUM 



By Georg Ochs 

 Of Frankfurt am. Main, Gennany 



I have to thank the authorities in charge of the entomological col- 

 lection of the United States National Museum for permission to work 

 upon the foreign species of Gyrinidae in that Museum. 



The material sent me contained several new forms, descriptions of 

 which are given below. There were also represented many other 

 species, already known, which are likewise treated so far as they gave 

 reason for special remarks. 



AULONOGYRUS CONSPICUUS, new species 



Length: 7% to 8^4 mm. Oval, hardly elongate, moderately con- 

 vex. Upper surface dark green, head and prothorax bluish with 

 coppery and purplish reflections, side margin rufous; under surface 

 dark, mesosternum, anal segment and legs rufous, epipleura yellow. 

 Labrum transverse, coppery-green, shining, finely alutaceous, an- 

 terior margin with long whitish hairs; clypeus coppery, strongly 

 alutaceous and punctate; head bluish, indistinctly alutaceous, vermi- 

 formly wrinkled and punctate, laterally coppery-aeneous, purplish 

 and more distinctly alutaceous and punctate near the eyes; prothorax 

 with bluish reflections, indistinctly alutaceous and strongly punctate, 

 in the middle transversely impressed and longitudinally channeled, 

 laterally with a purplish and strongly alutaceous spot, the rufous 

 side margin anteriorly larger than posteriorly; scutellum purplish, 

 shining ; suture of elytra coppery, truncature convex with obtuse and 

 scarcely rounded angles, each elytron with ten coppery sulci, which 

 are strongly alutaceous, serially punctured and apically united two 

 and two, the outer ones being more strongly impressed, intervals not 

 distinctly alutaceous, but strongly punctate, the eighth and tenth 

 narrower than the others; anterior tibiae curved inwards, the outer 

 margin apically dilated after the middle of length, apex obliquely 

 truncate, external apical angle obtuse, scarcely produced. 



No. 2774.— Proceedings U. S. National Museum, Vol. 75, Art. 3. 



22176—28 1 



