4868 Insects. 



preceding, from which it is readily distinguished by its more dilated 

 form, and a black transverse band at the base of thorax ; the markings 

 on elytra are somewhat differently arranged ; apex less acute. Ostend ; 

 brackish water.) 



10. H. conflnis, Steph. H. lineatus, Aube, Erich. Long. 3j ; 

 larg. 2. Allied to, and often confounded with, H. obliquus ; smaller, 

 narrower, more obtuse; thorax with a small longitudinal stria on 

 either side near the margin ; the dark lines of the striae of elytra 

 are less interrupted, so that the markings on the elytra are less 

 distinct and well defined. 



11. H. lineatocollis, Marsh, GylL, Steph., Aube. H. bistriolatus, 

 Dafts. Long. 3 ; larg. If. The black anterior margin of thorax, 

 and longitudinal line (which sometimes is an ill-defined cloud) along 

 the centre of its disk, sufficiently point out this abundant species. 



Genus Gyrinus. 



1. G. marinus, GylL, Ahr., Erich., Aube. G. natator, Fab., not Linn. 

 G. aeneus, Steph., not Aube. G. aeratus, Steph. G. dorsalis, GylL, 

 var. Taken throughout Great Britain. 



2. G. natator, Linn., GylL, Steph. G.substriatus, Steph. Abundant. 

 (G. nitens, Stiff. G. aeneus, Aube. Long. 5^ — 7; larg. 3j. 



Of the form, tint and punctuation of G. natator, from which it 

 differs by the dark metallic colour of the lower part of the body, 

 and also by the extremity of the elytra, of which the external angle is 

 straight, not rounded : it is also allied to G. marinus, from which it 

 is distinguished by its greater convexity, its colour more metallic 

 and brilliant, and by the lines of points, of which those nearer the 

 suture are less perceptible. Italy, Spain, middle of France; erro- 

 neously quoted as British.) 



(G. distinctus, Aube, Fairmaire. Long. 6| ; larg. 3j. Head and 

 thorax the same as G. natator; it differs by its form, more elongated, 

 somewhat less convex, breast and last ventral segment piceo-ferru- 

 ginous. The whole of Europe.) 



3. G. minutus, Fab., GylL, &c. Not common. Devonshire ; near 

 London ; Netley ; near Newcastle ; water of Leith ; near Edinburgh ; 

 Paisley : T took a fine series in a lake in Mull. 



4. G. bicolor, Payk., GylL, Curt., Steph. G. angustatus, Aube. 

 Norfolk, Suffolk ; Sheerness, in abundance ; salt lakes in Devon- 

 shire. 



5. G. urinator, Illig., Aube. G. lineatus, Steph. Slapton Ley 

 1 have also received specimens from Mr. Bold, from Ouseburn. 



