11 



Genus [90]. Hygrotus. Steph. Ten species. 



H. confluens. Fab. Testaceous ; head slightly darker, with 

 the occiput black or dusky ; elytra with five black, longi- 

 tudinal, parallel line3, the first and third from the suture 

 abbreviated in front, and all confluent behind ; If line ; 

 common. PI. 13, Jig. 1. 



Genus [91]. Hydroporus. Clairv. Forty-four species. 



H. 12. pustulatus, Fab. Ochraceous, the thorax with a 

 basal bilobate, black mark ; elytra also black and each 

 with six pale spots, three sutural and three marginal; 

 three lines ; ponds and ditches. PI. 13, Jig. 2. 



Group II. COLYMBETINI. Erichson. 



Genus [92]. Noterus. Clairv. Two species. 



N. crassicornis, Fab. Ferruginous ; elytra darker, with 

 their margin pale ; 2 j lines ; ponds and ditches. PI. 13, 



fig- 3- 



Genus [93]. Laccophiltjs. Leach. Two species. 



L. minutus, Lin. Testaceous-yellow; the elytra fuscous 

 with the margin and some irregular discoidal spots, paler; 

 two lines; ponds and ditches. PI. IB, Jig. 4. 

 Genus [94]. Agabus. Leach. Twenty-nine species. In the 

 type only are the antennae in the male serrated ; in the female 

 the antennae and feet are always simple. The genus is also di- 

 vided into sections and subsections from the acetabula of the 

 underside of the male anterior tarsi and the ciliation of their 

 posterior tarsi. 



A. serricornis, Payh. Pitchy; the lateral margins of the 

 thorax and elytra rusty red ; six lines; very rare, Shrop- 

 shire. PI. 13, fig. 5." 

 Genus [95]. Ilybius. Erichs. Six species. 



I. ater, Fab. Black, subeeneous, the external margins red- 

 dish brown ; the elytra with two pale pellucid spots ; six 

 lines; common. PI. 13, fig. 6. 

 Genus [96]. Colymbetes. Clairv. Six species. Anterior 

 tarsi of male with three dilated joints. 



C. striatus, Lin. Fuscous; thorax ferruginous, black in the 

 centre ; margins of elytra testaceous and legs black ; eight 

 lines; ponds and ditches, common. PI. 14, fig. 1. 



Group III. DYTISCINI. Erichson. 



Genus [97]- Dytiscus. Lin. Five species. In the female 

 anterior tarsi simple, and elytra usually furrowed longitudinally. 



