606 On Aquatic Carmvorous Coleoptera or Dytiscide. 
I. 61.—Genus SCUTOPTERUS. 
Side pieces of the tourth and following ventral segments comparatively broad, 
that of the fourth segment being only about twice as long as broad. Upper surface 
reticulate, black in colour. 
The two species are North American. 
918. Agabus angustus, Lec., Scutopterus angustus, M.C.—Suboblongus, parum 
convexus, vix nitidus, nigro-piceus, antennis palpisque piceo-rutis, pedibus piceis, 
capite anterius anguste rufescente, in medio verticis macula parva, 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 pubescence, their fourth joint is also dilated 
and short, the claws are simple and rather short: the anterior tibize have a deep 
emargination on their inner edge a little below the knee, the female I have not 
seen. 
The species is very distinct by a number of characters, from S. horni; it is of 
rather narrower and more depressed form, and less intensely black in colour and 
less shining ; the reticulation on the elytra forms smaller meshes, and the serial 
punctures are less distinct especially behind ; the thorax shows a sharper lateral 
margin; the antenne are rather more slender and elongate ; the hind cox are 
rather larger, but their anterior border is less arched, the wings of the metasternum 
are considerably 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. 405.—Suboblongus, 
niger, nitidus, antennis palpisque rufis, 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 tibize have a 
deep emargination on their mner edge a little below the knee. The female 
