606 On Aquatic Carnivorous Coleopte)-a or Dytiscidce. 



I. (ii. —Genus SCUTOPTERU.S. 



Side pieces of the fourth and following ventral segments coaiparatively broad, 

 that of the fourth segment being only about twice as long as broad. Upper suiface 

 reticulate, black in colour. 



The two species are North American. 



• 918. Agabus angustus, Lee, Scutopterus angustus, M.C. — Suboblongus, parum 

 convexus, vix nitidus, nigro-piceus, auteunis palpisque piceo-rutis, pedibus piceis, 

 caj^ite anterius anguste rufescente, in medio verticis macula jjarva, prothoracis 

 marginibus vage picescentibus ; prothorace basi subtruncato ; corpore supra (in 

 elytris profundius) reticulato, elytris punctis seriatis tantum anterius sat conspicuis. 

 Long. 16, lat. 8 m.m. 



The male has the three basal joints of the front and middle tarsi much dilated 

 and scarcely compressed, and furnished beneath with four series of palettes, and 

 with a large basal patch of glandular puhe.scence, their fourth joint is also dilated 

 auil short, the claws are simple and rather short : the anterior tibiae have a deep 

 emargination on their inner edge a little below the knee, tlie female I have not 



seen 



The species is very di.stinct by a number of chai-acters, from 8. horni ; it is of 

 rather narrower and more depressed form, and less intensely black in colour and 

 less shining ; the reticulation on the elytra ioi-ms smaller meshes, and the serial 

 punctures are less distinct especially behind ; the thorax shows a sharper lateral 

 margin ; the antennae are rather more slender and elongate ; the hind coxae are 

 rather larger, but their anterior border is less arched, the wings of the metasteruum 

 are considei'ably larger, and the hind legs are more elongate and slender. 



North America, (Lake Superior, Kansas, Canada ; fide Crotch). 927. 



919. Scutopterus horni. Crotch, Tr. Am. Ent. Soc. IV, p. 40.5. — Suboblongus, 

 niger, nitidus, antennis palpisque ruhs, pedibus piceis, capite ad angulos clypei et 

 in medio verticis parum discrete rufescente ; prothorace basi subtruncato ; corpore 

 supra, (in elytris profundius) reticulato, elytris punctis seriatis etiam ad apicem 

 conspicuis. Long. 16, lat. 8 m.m. 



The male has the three basal joints of the front and middle tarsi much dilated, 

 and scarcely at all compressed, and furnished beneath with four series of palettes, 

 and with a large basal patch of glandular pubescence, their fourth joint is also 

 dilated and short, the claws are simple and rather short ; the anterior tibiae have a 

 deep emargination on their inner edge a little below the knee. The female 



