560 HYDROMETRINA. 



nerves black, at the base with yellow hairs. Sternum ; Prosternum 

 depressed, yellow, with a fuscous shade in the middle ; Mesostcrnum 

 in front, between the coxae, with a narrow longitudinal channel, 

 which is widened and shallow posteriorly ; on the side of the coxal 

 sheaths a silvery line ; sides next the pronotum dull black, the colour 

 divided into 2 lines by a silvery streak ; sheath of the 2nd and 3rd 

 pairs of coxae black above, pale yellowish beneath. Legs ; 2nd pair 

 slightly the longest ; coxce black, the ends yellow-brown ; fulcra 

 yellow-brown, blackish in the centre; ihiglis black above, gray- 

 brown beneath ; 1st pair slightly yellow at the base ; 2nd pair shorter 

 than the 3rd ; tibia; 2nd pair longer than the 3rd ; tarsi; 2nd pair, 

 1st joint 3 times longer than the 2nd ; 3rd pair, 1st joint nearly twice 

 as long as the 2nd. 



Abdomen beneath, in the middle almost keeled, the sides of each 

 segment, except the last, on the posterior margin, with a short 

 silvery streak or spot ; the posterior margin of the 6th segment in 

 the $ with a somewhat right-angled excision ; in the $ only slightly 

 concave ; Connexivum on the margin narrowly yellow-brown ; the 

 terminal spine black, directed obliquely upwards, subequal in thick- 

 ness throughout, outwardly convex, inwardly concave, reaching 

 rather beyond the genital segments in both sexes ; in the $ a little 

 curved outwards at the base, but converging at the apex, which is 

 suddenly acute. Genital segments beneath; in the <, the 1st with 

 a tubercle ; 2nd long, semioval ; 3rd short, rounded ; in the $ , the 1st 

 yellow-brown, subtrapezoidal, the base convex ^ the sides much com- 

 pressed, hollow, with a subangulated prominence near each basal 

 angle ; 2nd black, semioval. 



Length, 5f 6J lines. 



Scarce. Locality not recorded. 



Species 2. HYDROMETRA NAJAS. 



CIMEX NAJAS, De G. Mem. iii, 313, 1. 16, fig. 9 (1773). 

 GERRIS APTERA, Schum. Beitr. 2, 34, 3, t. 4, figs. 4, 20 24 (1832). 

 CANALIUM, L. Duf. Recli. 69, t. 5, fig. 59 (1833); Am. et Scrv. 



Hem. 418, 3 (1843). 



PATJSARIUS, Curt. B. E. xii, 553, 2 (1835). 



HYDROMETRA APTERA, Bohem. Vet. Akad. Forh. 79, 38 (1853) ; Kolen. 

 Mel. Ent. vi, 58, 263 (1857); Flor, Rhyn. Liv. 

 i, 734, 2 (1800). 

 HYDROMETRA NAJUS, Fieb. Europ. Hem. 107, 3 (1861). 



