MADEIRAN COLEOPTERA. F 25 
Genus 27. AGABUS. 
Leach, Zool. Miscell. iii. 69. 72 (1817). 
73. Agabus bipustulatus*. 
Dytiscus bipustulatus, Linn., Syst. Nat. ii. 667 (1767). 
, Fab., Syst, Eleu. 1. 263 (1801). 
Agabus bipustulatus, 4ubé, Hydrocanth. 357 (1888). 
, Woll., Ins. Mad. 83 (1854). 




Inhabits the rivers and pools of Madeira proper, occurring at 
nearly all elevations. 
74. Agabus nebulosus*. 
Dytiscus nebulosus, Forster, Nov. Spee. Ins. 56 (1771). 
bipunctatus, Fab., Mant. Ins. 190 (1787). 
Colymbetes nebulosus, Steph., Ill. Brit. Ent. ii. 72 (1829). 
Agabus bipunctatus, dubé, Hydrocanth. 528 (1888). 
nebulosus, Woll., Ins. Mad. 84 (1854). 


Inhabits Madeira and the two northern Dezertas,—the typical 
state (in which the prothorax is immaculate) for these islands being 
that which is aberrant throughout Europe generally. It occurs also 
in the Canarian Group. 
75. Agabus Maderensis. 
Agabus Maderensis, Woll., Ins. Mad. 85 (1854). 
Inhabits the streams and Levadas of Madeira proper, attaining its 
maximum in the higher altitudes, though occurring towards the 
northern coast at a comparatively low elevation. 
Genus 28. HYDROPORUS. 
Clairville, Ent. Helv. ii. 183 (1806). 
76. Hydroporus vigilans. 
Hydroporus vigilans, Woll., Ins. Mad. 86 (1854). 
Inhabits the streams of Madeira proper, occurring abundantly at 
intermediate and lofty elevations, and descending on the northern 
side of the island to the level of the shore. 
+ Out of 51 specimens which I have lately examined (16 of which are from 
Madeira proper, 22 from the Ilheo Chao, and 13 from the Dezerta Grande), six 
only have the two prothoracie patches which are almost universally indicated in 
more northern latitudes, developed. Hence, the immaculate state must be 
regarded as typical for these islands; and the “var. 3,” therefore, of the 
Insecta Maderensia must take the precedence of the diagnosis. 
