584 On Aquatic Carnivorous Coleoptera or Dytiscide. 
Grovp 11. (Nos. 865 to 868). 
Elytra with a submarginal stria and with seven or eight other striz on 
each. 
The striw absent are these near the suture, but although the species agree fairly 
in this respect, it is pretty certain they are not really allied to one another; No. 
867 indeed seems by the nature of the coxal lines to approximate to C. australis 
of the first or estriate group ; and No. 868 is more probably allied to No. 848 
(eighth group). 
865. Copelatus chevrolati, Aubé, M.C.—Ovalis, elongatus, subdepressus, subtus 
nigro-piceus, capite thoraceque rufescentibus, hoe lateribus dilutioribus, elytris 
magis castaneis ; prothorace fere levi (in femina ad latera subtiliter rstrigoso) ; elytris 
striis octo soins alternis posterius abbreviatis, aliaque marginali anterius 
abbreviata. Long. 6, lat. 3} m.m. 
The male has the front and middle tarsi a good deal dilated, the front tibise 
nearly simple; the female has the sides of the thorax covered over a broad space 
with fine anastomosing striz. 
North America. (California, Arizona, Texas, Kansas, Lake Superior, sec. Crotch). 643. 
866. Copelatus validus, a. sp.—Oblongo-ovalis, sat latus, depressus, nitidus, niger, 
antennis pedibusque rufis, prothorace lateribus ely trorumque apice dileeionTous : 
elytris striis octo ante apicem desinentibus, prima a sutura remota, secunda disin- 
tegrata, aliaque marginali anterius et posterius abbreviata. Long. 73, lat. 4 m.m. 
I have seen but a single individual ; it is a female, and has the sides of the thorax 
rather densely covered with Sonate scratches, but the disc is quite smooth; a 
rather small area near the side of each wing case also is rather closely ees 
with distinct scratches. 
This species seems to be a large and dark-coloured one ; the first stria is about as 
far from the suture as the width of the first, second, third, and fourth interstices 
together ; the second stria is disintegrated and rudimentary, the second, fourth 
and sixth are considerably shorter than the others, and stop short about two-thirds 
of the length of the wing cases, the first, third, fifth, seventh and eighth are longer, 
but still stop short a good distance before the apex ; at the base the alee 
striz are more or less abbreviated : the submarginal stria is short and placed about 
the middle of the length. 
Central America, (Chontales, T. Belt). 1159. 
