538 On Aquatic Carnivorous Coleoptera or Dytisculce. 



758. Agabus regularis, Lee, M.C. — Ovalis, crassus, convexiusculus, piceus, supra 

 senesceus, antennis rufis ; supra undique deiisius ruiuus subtiliter retioulatus ; thorace 

 cum elytris continuo, antror«um angustato, margine lateral!, lato, huiuili ; elytris 

 pone medium vittula parum conspicua testacea ; antennis sat elougatis et gracilibus ; 

 pedibus posterioribus brevibus et crassis. Long. 11, lat. 61 m.m. 



The male has the three basal joints of the front and middle tarsi a good deal 

 incrassate, and furnished beneath with moderately short hairs, many of which bear 

 minute palettes. There is no sexual difference of sculpture. 



The species is remarkable by its short, thick, hind legs ; their development, indeed 

 for swimming organs is more advanced than in any species of Agabus. 



North America, (San Diego, California}. 831. 



I. 48.— Genus PLATYNECTES. 



Side of prothorax with a raised margin ; hind coxas very large, so that the wings of 

 the metasternum are greatly reduced, and are slender and linear : hind legs rather 

 long and slender ; epipleurae behind the middle very narrow. 



The thirteen species * of this genus form three groups, viz : — 



Group 1. — Ventral segments strigose ; prosternal process not broad nor Hat, but 

 somewhat compressed and carinate along the middle. Male tarsi 

 distinctly incmssate. L^p])er surface evidently reticulate. Species 

 inhabiting Australia and Tasmania. Nos. 759 to 702. 



Groui' 2.— Ventral segments polished prosternal process rather broad, nearly 

 flat, very acuminate. Species found in Australia and Asia. Nos. 

 763 to 766. 



(tkoup 3. — Upper surface vei-y polished ; prosternal process broad, flat, but 

 little acuminate. Species found in South America. Nos. 767 to 7 71. 



Group 1. 



759. Platynectes tenescens, n. sp. — Ovalis, baud angustus, minus convexus, sat 

 nitidus, supra crebre subtiliter reticulatus, niger, supra fenescens, prothorace ad 

 latera vage angusteque ferrugineo, elytris macula sublaterali pone medium testacea, 

 antennis pedibusque rufis, thorace cum elytris omnino continuo, angulis pusterioribus 

 baud acutis ; prosterni processu angusto. Long. 6], lat. 4 m.m. 



* In addition to these it i.s probable tli:it tlic following names refer to species of this genus. Agabus 

 bakcwelli, Clark (No. 1181); Anstralia. — Agabus hignbris, Blanch. (No. ll!).5)?No. 763 var. ; Tasmania. 

 —Agabus tasmauise, Clark (No. 1203; near No. 704 ; Australia, Tasmania. — Col.ymbetes bneatus, Redt. 

 (No. 1237) I near No. 766 ; India. — Coljmbetes magellaniuus, Bab. (No. 1238) ; Patagonia. — Colymbetes 

 monostiguia, Hope (No. 1 210), gen. dub. ; Australia. — Colymbetes octodecim-inaculatus, Mael. (No. 1242); 

 Java. — Colymbetes snbmacnlatus, Cast. (No. 1252) ; near No. 7G9 ; Cayenne. 



