356 JOHN HAMILTON, M. D. 



DYTISCID^. 

 Obs.— Hydrovatus ciispidiatus Kiiiize. — Dr. Sharp says tbat the species 

 kiiowii by this name in our literature is pitstulatus Mels.. and not the 

 true cuspidatus. Sharp, 323. 



68. Hygrotus insequalis Fab., punctatus Say. — This species is a little variable 

 in color ornamentation. It occurs here abundantly and generally 

 throughout the Middle and Western States (Buffalo, N. Y. ; Ottawa, 

 Canada; Lake Superior. Michigan, Ohio, Illinois, Kansas, Colorado). 

 Northern and central Europe. Sharp, 395; Turkestan, Heyden, 53; 

 Algeria, Wehnke (Sli.). T. iv, 387: var. punctatus is the form most 

 commonly met with. 



()!). H. impressopunctatus Schall., similis, picatus Kirbj', mgrolineatus t Kirby, 

 10-lineatus M.inu., porosus Gebl. — Apparently less abundant than the 

 preceding. Pennsylvania. Massachusetts, New York, Canada, Michigan, 

 Illinois, Lake Superior, Hudson Bay region, Sitka. Europe. Asia 

 Minor, northern and southern Siberia. T. iv, 389; Col. Am., 100; Sh., 

 403 ; Heyden, 54. 



70. Deronectes depressus Fab., rotundatus Lee, Cat. iv. Mr. Fauvel gives 



brevis Sturm, precedence. — Canada, Harrington; New York, Eeineckel 

 Michigan. Schwarz. Europe to 68° 20', in Lapland. T. iv, 392; Sh., 428. 



71. D. griseostriatus DeG., ? {cntascopium, interruptus, parallelus Say, A-striatus 



Eivh . , prosternal is, suffusus Sharp). — Thusconstituted the species extends 

 from Labrador to Alaska (Labrador Packard; Hudson Bay region, 

 Kirby; Alaska, California, Kansas, Lake Superior, LeConte; Michigan, 

 Schwarz; New York, Reinecke; Vermont, Pennsylvania. My specimens 

 are from Colorado and Massachusetts. Alpine and northern Europe to 

 69° iu Finland. Arctic Siberia (Dudinka). T. iv, 393; T. s, 277; Sh., 

 435; Heyden, 54. 



72. Hydroporus alpinus Payk., var. 12-Iineatus Lee, 'ilxvis Kirby. — Lake 



Superior. Canada; Ixvis, Hudson Bay region. Lapland and Norway 

 to 68°. Arctic Siberia. T. iv, 391; Sh., 448; Heyden, 54.— The exam- 

 ples before me can, by description, be referred partly to alpinus and 

 partly to 12-lineatus. Lsevis was taken presumably iu the Hudson Bay 

 region, and seemingly has not been duplicated, though possibly the form 

 taken by Dr. Bell in lat. 54° 53', long. 95° 44', determined by Dr. Le- 

 Conte (Lee. Cat.) to be alpinus, may have been this variety. Mr. Fauvel 

 seems to think alpinus and 12-lineatus distinct species. In uniting bo- 

 realis GyW. with alpinus in the former edition (which Mr. Fauvel says 

 was an error), I merely gave the statement of Dr. Sharp (448j. 



73. H. septentrionalis Gyll., scitulus Lee. — Lake Superior (l^eConte, Scliwarz), 



Idaho, Wickham. The mountains and northern parts of Europe. 

 Eastern Siberia, the Amur, Dauria. P. vii, 295; Sh., 449; Heyden, 54. 



74. H. Sanmarkii Sahib., var. rivalis Gyll. (obesus, congruus Lee.) var. alienus 



Sharp. — This species is described from California and from Colorado 

 (Florissant at 8000 feet). Arctic Europe to 68° 50'. Central Europe. 

 Arctic Siberia (Dudinka and Chantaika Rivers, affluents of the Jenisei, 

 69° 30' to 72°). Sharp, 449; Heydei', 54. Rivalis is the American form, 

 Hamnarhii the Siberian, while in Europe both are connected by indi- 

 viduals. Fauvel, 102. 



